Objective:To present a modified technique for robot-assisted laparoendoscopic single-site retroperitoneal nephroureterectomy(RLESS-RNU)with bladder cuff excision and evaluate its effectiveness as a minimally invasive ...Objective:To present a modified technique for robot-assisted laparoendoscopic single-site retroperitoneal nephroureterectomy(RLESS-RNU)with bladder cuff excision and evaluate its effectiveness as a minimally invasive approach for managing upper tract urothelial carcinoma(UTUC).Methods:Fifteen patients who underwent RLESS-RNU for UTUC between April 2020 and June 2021 were reviewed at our medical institution(The Second Affiliated Hospital of Nanjing Medical University,Nanjing,China),from our prospectively maintained institutional database.The da Vinci^(®)Xi system(Intuitive Surgical,Sunnyvale,CA,USA)was utilized for surgical procedures in all patients.An in-depth analysis was conducted on their baseline demographic characteristics,pathological factors,and perioperative details.The complete surgical process and details are elaborated.Results:The median age of 15 patients was 67 years.The final pathology demonstrated 47%(7/15)patients with pT1 or lower and 47%(7/15)with pT3;one patient could not undergo pathological staging because of preoperative chemotherapy.The perioperative outcomes revealed that the mean operative time was 185(standard deviation[SD]23.05)min.The mean times of the trocar placement for primary and second docking were 15.00(SD 0.85)min and 8.00(SD 0.52)min,respectively.The median estimated blood loss was 55 mL.The mean drainage tube duration and postoperative hospital stay were 7.50 days and 11.00 days,respectively.After a mean follow-up period of 24.20 months,the relapse-free survival rate was 87%.Two patients experienced disease progression:one patient exhibited multifocal evidence of non-muscle invasive bladder cancer,and the other patient developed systemic recurrence.Conclusion:This study demonstrates that the modified technique for RLESS-RNU is safe and satisfactory for UTUC.展开更多
Introducing functional polar groups into polyolefins can significantly improve the material properties,but there are still challenges in achieving this goal,with the core difficulty being that polar groups are prone t...Introducing functional polar groups into polyolefins can significantly improve the material properties,but there are still challenges in achieving this goal,with the core difficulty being that polar groups are prone to interact with metal active species,affecting the efficiency of the copolymerization.With the rapid advancement in catalyst,a variety of copolymerization strategies are developed aimed at producing more versatile polyolefin materials.Although early transition metal catalysts play an indispensable role in the traditional polyolefin industry,their inherent strong oxophilicity becomes a significant constraint in copolymerization involving polar olefins,limiting their application scope.This review summarizes the progress made in recent years in the efficient copolymerization of non-polar olefins with polar comonomers catalyzed by groups 3 and 4 single-site catalysts.We classify the catalysts into four categories,Sc-,Ti-,Zr-,Hf-,based on the type of metal centers,and provide insights into the influence of catalyst structures and the type of comonomers on the copolymerization behavior.The introduction of polar monomers fundamentally improves the comprehensive performance of the products,greatly broadens the application scope of polyolefin materials,and meets the growing market demand for multifunctional and high-performance materials.展开更多
Objective:Radical prostatectomy(RP)is considered the gold standard treatment for patients with localized prostate cancer(PCa).All patients undergoing RP,either open,laparoscopic,or robotic,are at risk of developing ur...Objective:Radical prostatectomy(RP)is considered the gold standard treatment for patients with localized prostate cancer(PCa).All patients undergoing RP,either open,laparoscopic,or robotic,are at risk of developing urinary incontinence after RP.Our study aimed to analyze possible predictors of early postoperative(within 3 months)urinary continence(UC)outcomes following extraperitoneal single-site robot-assisted RP(ss-RARP)for localized PCa.Methods:We retrospectively reviewed data from 113 patients with localized PCa who were operated on by a highly experienced surgeon between September 2022 and December 2023.Patient characteristics(age,body mass index,prostate volume,prostate dimensions,preoperative and postoperative membranous urethral length,and percentage of membranous urethra removed)were analyzed using logistic regression to determine the independent factors contributing to short-term UC recovery after extraperitoneal ss-RARP.From the time of urinary catheter removal after surgery,the recovery of UC was followed up every month,and UC was defined as using≤1 safety pad daily,known as social continence.Results:The proportions of continent patients immediately after urinary catheter removal,1 month,and 3 months after extraperitoneal ss-RARP were 22%,49%,and 82%,respectively.The multivariate logistic regression analysis showed that the percentage of membranous urethra removed(p=0.016)and prostate volume(p=0.049)were associated with social UC recovery immediately after urinary catheter removal,and craniocaudal dimension of the prostate(p=0.042)and age(p=0.014)were associated with social UC recovery 1 month and 3 months after extraperitoneal ss-RARP,respectively.Conclusion:The percentage of membranous urethra removed,prostate volume,craniocaudal dimension of the prostate,and age are independent risk factors for social UC early after extraperitoneal ss-RARP.展开更多
This paper presents a single-site positioning method based on the joint estimation of propagation time-of-arrival(TOA) and direction-of-arrival(DOA), with the assist of virtual stations in the typical non-line-of-sigh...This paper presents a single-site positioning method based on the joint estimation of propagation time-of-arrival(TOA) and direction-of-arrival(DOA), with the assist of virtual stations in the typical non-line-of-sight(NLOS) environment. Consider the influence of multipath noise on the positioning performance, the proposed method firstly presents a modified high-resolution estimation technique called Multipath noise Limiting Matrix Pencil(MLMP) algorithm to achieve the TOA/DOA estimations, in which the matrix pencil and matrix enhancement process are implemented to deal with the measurements from the uniform linear array(ULA) receiver. Meanwhile, the subspace dimension estimation is improved via an adaptive threshold, for enhancing the performance of high-resolution techniques in low signal-noise-ration(SNR) situation. Next the proposed method generates virtual stations utilizing the known floor plan of surrounding reflectors, and adopts a weighted Least Square(WLS) position estimator to calculate the required position, combining the TOA/DOA estimations with the location of virtual stations. Simulations are conducted to evaluate the proposed method under NLOSconditions, and the results show that comparing with the multipath fingerprinting scheme, the proposed method has better performance in various simulation scenarios.展开更多
The present meta-analysis was conducted to compare the clinical effect and patient experience of laparoendoscopic single-site varicocelectomy （LESSV） and conventional laparoscopic varicocelectomy. The candidate stud...The present meta-analysis was conducted to compare the clinical effect and patient experience of laparoendoscopic single-site varicocelectomy （LESSV） and conventional laparoscopic varicocelectomy. The candidate studies were included after literature search of database Cochrane Library, PubMed, EMBASE, and MEDLINE. Related information on essential data and outcome measures was extracted from the eligible studies by two independent authors, and a meta-analysis was conducted using STATA 12.0 software. Subgroup analyses were conducted by study design （RCT and non-RCT）. The odds ratio （OR） or standardized mean difference （SMD） and their 95% confidence intervals （95% CIs） were used to estimate the outcome measures. Seven articles were included in our meta-analysis. The results indicated that patient who had undergone LESSV had a shorter duration of back to work （overall： SMD = -1.454, 95% Ch -2.502m0.405, P= 0.007; non-RCT： SMD = -2.906, 95% Ch -3.796-2.017, P= 0.000; and RCT： SMD = -0.841, 95% Ch -1.393-0.289, P = 0.003） and less pain experience at 3 h or 6 h （SMD = -0.447, 95% Ch -0.754-0.139, P = 0.004）, day 1 （SMD = -0.477, 95% Ch -0.905-0.05, P = 0.029）, and day 2 （SMD = -0.612, 95% Ch -1.099-0.125, P= 0.014） postoperatively based on RCT studies. However, the meta-analyses based on operation time, clinical effect （improvement of semen quality and scrotal pain relief）, and complications （hydrocele and recurrence） yielded nonsignificant results. In conclusion, LESSV had a rapid recovery and less pain experience over conventional laparoscopic varicocelectomy. However, there was no statistically significant difference between the two varicocelectomy techniques in terms of the clinical effect and the incidence of hydrocele and varicocele recurrence. More high-quality studies are warranted for a comprehensive conclusion.展开更多
The laparoendoscopic single-site （LESS） technique is the latest technical innovation in laparoscopic surgery to undergo exponential development in urology. This study undertaken to illustrate our initial experience ...The laparoendoscopic single-site （LESS） technique is the latest technical innovation in laparoscopic surgery to undergo exponential development in urology. This study undertaken to illustrate our initial experience LESS radical prostatectomy （RP） and analyze early outcomes. Nineteen patients diagnosed with prostate cancer underwent LESS-RP in our institute. The patients were divided into two groups： conventional LESS and transurethral assistant LESS. Preoperative, perioperative, postoperative, pathologic, and functional outcomes data were assessed. With the help of a transurethral assistant, the mean operation and anastomosis time were decreased markedly. No focal positive margins were encountered. No prostate-specific antigen recurrence was detected 1 month postoperatively. Complete continence recovery （no pad） was observed in 32% of the patients at 1 month after the operation. No intraoperative and postoperative complications were reported, LESS-RP is a feasible and effective surgical procedure for treatment of prostate cancer. Moreover, transurethral assistant LESS could reduce the difficulty of LESS-RP and shorten the operation time.展开更多
Objective This prospective single-arm clinical trial aimed to evaluated the feasibility and safety of the application of the SHURUI system(Beijing Surgerii Technology Co.,Ltd.,Beijing,China),a novel purpose-built robo...Objective This prospective single-arm clinical trial aimed to evaluated the feasibility and safety of the application of the SHURUI system(Beijing Surgerii Technology Co.,Ltd.,Beijing,China),a novel purpose-built robotic system,in single-port robotic radical prostatectomy.Methods Sixteen patients diagnosed with prostate cancer were prospectively enrolled in and underwent robotic radical prostatectomy from October 2021 to August 2022 by the SHURUI single-port robotic surgical system.The demographic and baseline data,surgical,oncological,and functional outcomes as well as follow-up data were recorded.Results The mean operative time was 226.3(standard deviation[SD]52.0)min,and the mean console time was 183.4(SD 48.3)min,with the mean estimated blood loss of 116.3(SD 90.0)mL.The mean length of postoperative hospital stay was 4.50(SD 0.97)days.Two patients had postoperative complications(Clavien-Dindo Grade II),and both patients improved after conservative treatment.All patients’postoperative prostate-specific antigen levels decreased to below 0.2 ng/mL 1 month after discharge.The mean prostate-specific antigen level further decreased to a mean of 0.0219(SD 0.0641)ng/mL 6 months after surgery.Thirty days postoperatively,12 out of 16 patients reported using no more than one urinary pad per day,and all patients reported satisfactory urinary control without the need for pads 6 months after surgery.Conclusion The SHURUI system is safe and feasible in performing radical prostatectomy via both transperitoneal and extraperitoneal approaches.Tumor control and urinary continence were satisfying for patients enrolled in.The next phase involves conducting a large-scale,multicenter randomized controlled trial to thoroughly assess the effectiveness and safety of the new technology in a broader population.展开更多
AIM To evaluate the feasibility,safety and peri-and postoperative outcomes of robotic single-site supracervical hysterectomy(RSSSH) for benign gynecologic disease.METHODS We report 3 patients who received RSSSH for ad...AIM To evaluate the feasibility,safety and peri-and postoperative outcomes of robotic single-site supracervical hysterectomy(RSSSH) for benign gynecologic disease.METHODS We report 3 patients who received RSSSH for adenomyosis of the uterus from November 2015 to April 2016.We evaluated the feasibility,safety and outcomes among these patients.RESULTS The mean surgical time was 244 min and the estimated blood loss was 216 mL,with no blood transfusion necessitated.The docking time was shortened gradually from 30 to 10 min.We spent 148 min on console operation.Manual morcel ation time was also short,ranging from 5 to 10 min.The mean hospital stay was 5 d.Lower VAS pain score was also noted.There is no complication during or after surgery.CONCLUSION RSSSH is feasible and safe,incurs less postoperative pain and gives good cosmetic appearance.The technique of inbag,manual morcellation can avoid tumor dissemination.展开更多
Background： Laparoendoscopic single-site surgery （LESS） may serve as a potential alternative to conventional laparoscopy and is developing quickly, but still in its infancy. The study is to present our two-year exp...Background： Laparoendoscopic single-site surgery （LESS） may serve as a potential alternative to conventional laparoscopy and is developing quickly, but still in its infancy. The study is to present our two-year experience in transumbilical LESS simple nephrectomy （LESS-SN） for non-functioning kidney, in an effort to evaluate its feasibility, clinical outcomes and potential advantages. Methods： From December 2008 to December 2010, a total of 11 patients with body mass index （BMI）≤30 underwent transumbilical TriPortTM LESS-SN by a single experienced urologist at our institution. The indications for nephrectomy included nonfunctioning kidney associated with ureteropelvic junction stricture （n=l）, ureteral calculi （n=6）, tuberculosis （n=3）, and ureteral stricture （n=l）. Patient demographics perioperative and follow-up data were prospectively collected and analyzed. Results： Ten procedures were successfully completed with one patient converted to open surgery due to uncontrollable bleeding. The mean operative time was 189.2 （ranging 100-320 min） with an estimated blood loss of 204.5 （ranging 50-1 000 ml）. There were two complications of bleeding （1- intra-, 1- post-）. The mean hospitalization after surgery was 7.9 d （ranging 4-17 d） With a regular follow-up of 1, 6, 12, and 24 months after surgery, all patients remained symptom-free with an intra-umbilical scar. Conclusion： Transumbilical LESS simple nephrectomy for nonfunctioning kidney can be accomplished with favorable surgical outcomes and a superiority of cosmesis. However, cases with chronic inflammation are not suitable for initial up-take and should only be attempted by the very experienced laparoscopist.展开更多
Objective： To describe two cases of bilateral transumbilical laparoendoscopic single-site（LESS） surgeries in a single operative session and assess the safety, feasibility and efficacy. Methods： One patient underwe...Objective： To describe two cases of bilateral transumbilical laparoendoscopic single-site（LESS） surgeries in a single operative session and assess the safety, feasibility and efficacy. Methods： One patient underwent right ureterolithotomy and left varicocelectomy, and the patient was performed with right simple nephrectomy for nonfunctioning kidney due to ureteral calculus and left ureterolithotomy using a novel multichannel TriPortTM via a single 2-3 cm transumbilical incision Results： The right-side ureterolithotomy and left-side varicocelectomy were finished in 229 minutes, with a total estimated blood loss of 50 hal. The right-side simple nephrectomy and left-side ureterolithotomy in the other patient were finished in 340 minutes, with a total estimated blood loss of 100 ml. There were no major complications. At the latest follow-up, both patients remained symptom-free and there were no evidences of recurrence. Both of them were delighted for the single scarConclusion： Synchronous LESS urologic procedure via a single umbilical incision is technically feasible, safe and efficacious with a promising potential展开更多
Objective:Nephron-sparing surgery(NSS) for small renal masses offers a similar functional and oncological outcome to that of radical surgery.Laparoendoscopic single-site surgery(LESS) emerges as an advanced alternativ...Objective:Nephron-sparing surgery(NSS) for small renal masses offers a similar functional and oncological outcome to that of radical surgery.Laparoendoscopic single-site surgery(LESS) emerges as an advanced alternative for reduced invasiveness and improves cosmesis;LESS is developing quickly and its indications have been expanded,but still in its infancy.The aim of this paper is to report our preliminary experience in transumbilical LESS partial nephrectomy(LESS-PN),so as to assess its utility, safety and efficacy.Methods:From August 2009 to October 2010,3 patients underwent transumbilical LESS-PN via a novel multi-channel TriPort by a single experienced urologist in our institution.Patient demographics,perioperative and follow-up data were prospectively collected and analyzed.Results:All the three procedures were successfully completed.A 5-mm ancillary trocar was utilized in all 3 cases.The mean operative duration was 226.3(210-254 min) with an estimated blood loss of 56.7 ml (20-100 ml).Mean warm ischemia time was 35.7 min(19-48 min).One patient was transfused due to postoperative bleeding. The recovery was uneventful and mean length of postoperative stay was 13 days(12-14 days).At the latest follow-up,all patients remained symptom-free and had normal renal function without evidence of recurrence,and they were delighted for a hidden transumbilical scar.Conclusion:Transumbilical LESS-PN is a feasible and safe procedure albeit extremely technically challenging.Surgical outcomes at a median follow-up of 2 years are promising,while currently it should be reserved for highly selected patients with favorable tumor anatomy and performed by a very experienced laparoscopic surgeon.展开更多
LaparoEndoscopic Single-site(LESS) renal surgery emerging as a potential alternative to conventional laparoscopy,is technically challenging and the major vascular anomaly may increase the risk of intraoperative haemor...LaparoEndoscopic Single-site(LESS) renal surgery emerging as a potential alternative to conventional laparoscopy,is technically challenging and the major vascular anomaly may increase the risk of intraoperative haemorrhage.Herein,we present a case of right transumbilical LESS radical nephrectomy which was successfully performed in the presence of double inferior vena cava and duplicated the standard laparoscopic techniques.Most importantly,to bring such an aberrant vascular anatomy to the attention of laparoscopic,especially LESS surgeons with high resolution pictorial illustrations.展开更多
Aim: To present our initial experience of applying laparoendoscopic single-site surgery (LESS) nephrolithotomy in the treatment of renal calculi. Methods: In August 2010 and April 2012, the LESS nephrolithotomy techni...Aim: To present our initial experience of applying laparoendoscopic single-site surgery (LESS) nephrolithotomy in the treatment of renal calculi. Methods: In August 2010 and April 2012, the LESS nephrolithotomy technique was applied to treat two patients with a renal calculus. One patient had a calculus measuring 5 × 3 cm, and the second patient's measured 3 × 3 cm. Both patients underwent general anesthesia. The operations were performed through a retroperitoneal approach with a single-port instrument inserted through the retroperitoneal incision. The standard laparoscopic retroperitoneal technique was performed, and the calculi were removed by incising the area of the thin renal cortex and the renal pelvis, respectively. The operating time, estimated blood loss, intraoperative complications, other complications, drainage time, and post-operative hospital stay were recorded. Results: Both procedures were completed successfully. No additional trocars were added. No conversion to standard laparoscopic or open surgery was needed. The operating times were 130 min and 120 min, and the estimated blood losses were 40 mL and 30 mL. There were no intraoperative complications. The wound drainage times were 3 d and 2 d, respectively and the post-operative hospital stays were 8 d and 7 d, respectively. There was no secondary bleeding or wound infection. Follow-up times were 2 years and 3 months, respectively. No incidence of hydronephrosis was recorded. Conclusions: LESS nephrolithotomy is safe and feasible for treating kidney calculi. It can be applied in patients with large renal calculi and regionally thin renal parenchyma.展开更多
AIM:To review an evolution of laparoscopic surgery,there has been a growing interest in laparoendoscopic single-site surgery(LESS).METHODS:A comprehensive electronic literature search was conducted using PubM ed datab...AIM:To review an evolution of laparoscopic surgery,there has been a growing interest in laparoendoscopic single-site surgery(LESS).METHODS:A comprehensive electronic literature search was conducted using PubM ed database to identify all publications relating to LESS-partial nephrectomy(PN).The research includes articles published from April 2008 to January 2014.We focused our attention only on articles in which were cited the single-site surgical technique(laparoscopic and robotic),tumour stage and grade,mean tumour size,intraoperative variables,blood loss and transfusion rate,length of postoperative stay and complication rates,Clavien classification,positive of surgical margins,pain assessment at discharge.RESULTS:A total of 9 studies were collected with 221patients included.The mean patients age was 62 years.The mean tumor size was 2.35 cm with a mean operative time of 181 min(range 111-270 min)and 58.3%were done by robot.The mean ischemia time was 23.6min.The 25.8%of patients underwent an unclamp LESS-PN.Mean estimated blood loss was 296 mL and median length of hospital stay was 4 d.The rate of severe post-operative complications(≥Clavien gradeⅢ)was 5.4%.Not all surgical series of LESS-PN or Robotic-LESS-PN shows conversion in Multiport Laparoscopic or Open Surgery.Regarding oncologic outcomes,surgical margins were positive 4%of patients(9/221),no distant or port-site metastases were recorded.CONCLUSION:LESS-PN and RLESS-PN are feasible and associated with reduced postoperative pain,shorter median hospital stay,shorter recovery time,and better cosmetic satisfaction without compromising surgical and oncological safety.展开更多
Within the advance ports and instruments, laparoendoscopic single-site (LESS) surgery has been increasingly used among gynaecologic surgeons. In addition, advanced port systems have enabled to perform concomitant surg...Within the advance ports and instruments, laparoendoscopic single-site (LESS) surgery has been increasingly used among gynaecologic surgeons. In addition, advanced port systems have enabled to perform concomitant surgical procedures via transumbilical incision. However, combined surgical operations are rarely reported in the literature, particularly in gynaecology. This case report presents a 42-year-old woman who undergo concomitant LESS hysterectomy and nephrectomy due to deep infiltrating endometriosis (DIE) and end stage renal disease. The operation is performed in approximately 3 hours without any complications, and the patient is discharged on postoperative third day. This case demonstrates that complex concomitant operations even in a patient with DIE can be performed using a LESS surgical approach.展开更多
Electrocatalytic reduction of nitrate(NO_(3)^(−))is a promising approach to achieving sustainable and green ammonia synthesis and environmental denitrification.Here,click chemistry is extended to fabricate dynamic sin...Electrocatalytic reduction of nitrate(NO_(3)^(−))is a promising approach to achieving sustainable and green ammonia synthesis and environmental denitrification.Here,click chemistry is extended to fabricate dynamic singlesite metal catalysts for NO3−electroreduction.Specifically,Co^(2+)-coordinated molecular units are covalently clicked into a stable Th-metal–organic framework,confining and dispersing single-site metals that exhibit the asymmetrical Co–N2Cl2 coordination configuration.The obtained CoN2Cl2@Th-BPDC electrocatalyst achieves an outstanding ammonia production rate of 770.3μmol h^(−1) cm^(−2)(5135.3 mmol gcat^(−1) h^(−1))at−0.4 V versus RHE,which is approximately 25.7 times higher than that of the Haber–Bosch process(<200 mmol gcat^(−1) h^(−1))and outperforms the most recently reported electrocatalysts.Theoretical calculations reveal that single-site Co2+exhibits strong bidentate adsorption toward NO_(3)^(−)due to the suitable geometric space provided by the rotation of Co-coordinated Cl atoms(a dynamic feature),which promotes NO_(3)^(−)activation and decreases the reaction barrier,resulting in excellent catalytic activity.This study describes an innovative strategy for fabricating dynamic asymmetrical single-site metal electrocatalysts and may inspire new methodologies for the precise synthesis of advanced catalytic materials.展开更多
The key challenge for scalable production of hydrogen from water lies in the rational design and preparation of high-performance and earth-abundant electrocatalysts to replace precious metal Pt and IrO_(2) for hydroge...The key challenge for scalable production of hydrogen from water lies in the rational design and preparation of high-performance and earth-abundant electrocatalysts to replace precious metal Pt and IrO_(2) for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Although atomic M-N-C materials have been extensively studied in heterogeneous catalysis field,the insufficient antioxidant capacity of carbonous substrates hinders their practical application in OER.Developing highly active and stable OER electrocatalysts is the key for electrochemical water splitting.This review presents feasible design strategies for fabricating carbon-free single-site catalysts and their applications in HER/OER and overall water splitting.The constitutive relationships between structure,composition,and catalytic performance for HER and OER are detailly discussed,providing ponderable insights into rationally constructing high-performance HER and OER electrocatalysts.The perspectives on the challenges and future research orientations in single-site catalysts for electrochemical water splitting are suggested.展开更多
Metal-nitrogen-carbon materials are promising catalysts for CO2 electroreduction to CO. Herein, by taking the unique hierarchical carbon nanocages as the support, an advanced nickel-nitrogen-carbon single-site catalys...Metal-nitrogen-carbon materials are promising catalysts for CO2 electroreduction to CO. Herein, by taking the unique hierarchical carbon nanocages as the support, an advanced nickel-nitrogen-carbon single-site catalyst is conveniently prepared by pyrolyzing the mixture of NiCl2 and phenanthroline, which exhibits a Faradaic efficiency plateau of > 87% in a wide potential window of −0.6 – −1.0 V. Further S-doping by adding KSCN into the precursor much enhances the CO specific current density by 68%, up to 37.5 A·g−1 at −0.8 V, along with an improved CO Faradaic efficiency plateau of > 90%. Such an enhancement can be ascribed to the facilitated CO pathway and suppressed hydrogen evolution from thermodynamic viewpoint as well as the increased electroactive surface area and improved charge transfer fromkinetic viewpoint due to the S-doping. This study demonstrates a simple and effective approach to advanced electrocatalysts by synergetic modification of the porous carbon-based support and electronic structure of the active sites.展开更多
The atomically dispersed Fe^(3+)sites of Fe-N-C single-site catalysts(SSCs)are demonstrated as the active sites for CO_(2)electroreduction(CO_(2)RR)to CO but suffer from the reduction to Fe^(2+)at~−0.5 V,accompanied b...The atomically dispersed Fe^(3+)sites of Fe-N-C single-site catalysts(SSCs)are demonstrated as the active sites for CO_(2)electroreduction(CO_(2)RR)to CO but suffer from the reduction to Fe^(2+)at~−0.5 V,accompanied by the drop of CO faradaic efficiency(FECO)and deterioration of partial current(JCO).Herein,we report the construction of F-doped Fe-N-C SSCs and the electron-withdrawing character of fluorine could stabilize Fe3+sites,which promotes the FECO from the volcano-like highest value(88.2%@−0.40 V)to the high plateau(>88.5%@−0.40-−0.60 V),with a much-increased JCO(from 3.24 to 11.23 mA·cm^(−2)).The enhancement is ascribed to the thermodynamically facilitated CO_(2)RR and suppressed competing hydrogen evolution reaction,as well as the kinetically increased electroactive surface area and improved charge transfer,due to the stabilized Fe^(3+)sites and enriched defects by fluorine doping.This finding provides an efficient strategy to enhance the CO_(2)RR performance of Fe-N-C SSCs by stabilizing Fe^(3+).展开更多
文摘Objective:To present a modified technique for robot-assisted laparoendoscopic single-site retroperitoneal nephroureterectomy(RLESS-RNU)with bladder cuff excision and evaluate its effectiveness as a minimally invasive approach for managing upper tract urothelial carcinoma(UTUC).Methods:Fifteen patients who underwent RLESS-RNU for UTUC between April 2020 and June 2021 were reviewed at our medical institution(The Second Affiliated Hospital of Nanjing Medical University,Nanjing,China),from our prospectively maintained institutional database.The da Vinci^(®)Xi system(Intuitive Surgical,Sunnyvale,CA,USA)was utilized for surgical procedures in all patients.An in-depth analysis was conducted on their baseline demographic characteristics,pathological factors,and perioperative details.The complete surgical process and details are elaborated.Results:The median age of 15 patients was 67 years.The final pathology demonstrated 47%(7/15)patients with pT1 or lower and 47%(7/15)with pT3;one patient could not undergo pathological staging because of preoperative chemotherapy.The perioperative outcomes revealed that the mean operative time was 185(standard deviation[SD]23.05)min.The mean times of the trocar placement for primary and second docking were 15.00(SD 0.85)min and 8.00(SD 0.52)min,respectively.The median estimated blood loss was 55 mL.The mean drainage tube duration and postoperative hospital stay were 7.50 days and 11.00 days,respectively.After a mean follow-up period of 24.20 months,the relapse-free survival rate was 87%.Two patients experienced disease progression:one patient exhibited multifocal evidence of non-muscle invasive bladder cancer,and the other patient developed systemic recurrence.Conclusion:This study demonstrates that the modified technique for RLESS-RNU is safe and satisfactory for UTUC.
基金supported by the National Natural Science Foundation of China(No.U23B6011)。
文摘Introducing functional polar groups into polyolefins can significantly improve the material properties,but there are still challenges in achieving this goal,with the core difficulty being that polar groups are prone to interact with metal active species,affecting the efficiency of the copolymerization.With the rapid advancement in catalyst,a variety of copolymerization strategies are developed aimed at producing more versatile polyolefin materials.Although early transition metal catalysts play an indispensable role in the traditional polyolefin industry,their inherent strong oxophilicity becomes a significant constraint in copolymerization involving polar olefins,limiting their application scope.This review summarizes the progress made in recent years in the efficient copolymerization of non-polar olefins with polar comonomers catalyzed by groups 3 and 4 single-site catalysts.We classify the catalysts into four categories,Sc-,Ti-,Zr-,Hf-,based on the type of metal centers,and provide insights into the influence of catalyst structures and the type of comonomers on the copolymerization behavior.The introduction of polar monomers fundamentally improves the comprehensive performance of the products,greatly broadens the application scope of polyolefin materials,and meets the growing market demand for multifunctional and high-performance materials.
文摘Objective:Radical prostatectomy(RP)is considered the gold standard treatment for patients with localized prostate cancer(PCa).All patients undergoing RP,either open,laparoscopic,or robotic,are at risk of developing urinary incontinence after RP.Our study aimed to analyze possible predictors of early postoperative(within 3 months)urinary continence(UC)outcomes following extraperitoneal single-site robot-assisted RP(ss-RARP)for localized PCa.Methods:We retrospectively reviewed data from 113 patients with localized PCa who were operated on by a highly experienced surgeon between September 2022 and December 2023.Patient characteristics(age,body mass index,prostate volume,prostate dimensions,preoperative and postoperative membranous urethral length,and percentage of membranous urethra removed)were analyzed using logistic regression to determine the independent factors contributing to short-term UC recovery after extraperitoneal ss-RARP.From the time of urinary catheter removal after surgery,the recovery of UC was followed up every month,and UC was defined as using≤1 safety pad daily,known as social continence.Results:The proportions of continent patients immediately after urinary catheter removal,1 month,and 3 months after extraperitoneal ss-RARP were 22%,49%,and 82%,respectively.The multivariate logistic regression analysis showed that the percentage of membranous urethra removed(p=0.016)and prostate volume(p=0.049)were associated with social UC recovery immediately after urinary catheter removal,and craniocaudal dimension of the prostate(p=0.042)and age(p=0.014)were associated with social UC recovery 1 month and 3 months after extraperitoneal ss-RARP,respectively.Conclusion:The percentage of membranous urethra removed,prostate volume,craniocaudal dimension of the prostate,and age are independent risk factors for social UC early after extraperitoneal ss-RARP.
基金supported in part by the National Natural Science Foundation of China under Grants numbers 61471164, 61601122, 61741102 and 61571128
文摘This paper presents a single-site positioning method based on the joint estimation of propagation time-of-arrival(TOA) and direction-of-arrival(DOA), with the assist of virtual stations in the typical non-line-of-sight(NLOS) environment. Consider the influence of multipath noise on the positioning performance, the proposed method firstly presents a modified high-resolution estimation technique called Multipath noise Limiting Matrix Pencil(MLMP) algorithm to achieve the TOA/DOA estimations, in which the matrix pencil and matrix enhancement process are implemented to deal with the measurements from the uniform linear array(ULA) receiver. Meanwhile, the subspace dimension estimation is improved via an adaptive threshold, for enhancing the performance of high-resolution techniques in low signal-noise-ration(SNR) situation. Next the proposed method generates virtual stations utilizing the known floor plan of surrounding reflectors, and adopts a weighted Least Square(WLS) position estimator to calculate the required position, combining the TOA/DOA estimations with the location of virtual stations. Simulations are conducted to evaluate the proposed method under NLOSconditions, and the results show that comparing with the multipath fingerprinting scheme, the proposed method has better performance in various simulation scenarios.
文摘The present meta-analysis was conducted to compare the clinical effect and patient experience of laparoendoscopic single-site varicocelectomy （LESSV） and conventional laparoscopic varicocelectomy. The candidate studies were included after literature search of database Cochrane Library, PubMed, EMBASE, and MEDLINE. Related information on essential data and outcome measures was extracted from the eligible studies by two independent authors, and a meta-analysis was conducted using STATA 12.0 software. Subgroup analyses were conducted by study design （RCT and non-RCT）. The odds ratio （OR） or standardized mean difference （SMD） and their 95% confidence intervals （95% CIs） were used to estimate the outcome measures. Seven articles were included in our meta-analysis. The results indicated that patient who had undergone LESSV had a shorter duration of back to work （overall： SMD = -1.454, 95% Ch -2.502m0.405, P= 0.007; non-RCT： SMD = -2.906, 95% Ch -3.796-2.017, P= 0.000; and RCT： SMD = -0.841, 95% Ch -1.393-0.289, P = 0.003） and less pain experience at 3 h or 6 h （SMD = -0.447, 95% Ch -0.754-0.139, P = 0.004）, day 1 （SMD = -0.477, 95% Ch -0.905-0.05, P = 0.029）, and day 2 （SMD = -0.612, 95% Ch -1.099-0.125, P= 0.014） postoperatively based on RCT studies. However, the meta-analyses based on operation time, clinical effect （improvement of semen quality and scrotal pain relief）, and complications （hydrocele and recurrence） yielded nonsignificant results. In conclusion, LESSV had a rapid recovery and less pain experience over conventional laparoscopic varicocelectomy. However, there was no statistically significant difference between the two varicocelectomy techniques in terms of the clinical effect and the incidence of hydrocele and varicocele recurrence. More high-quality studies are warranted for a comprehensive conclusion.
文摘The laparoendoscopic single-site （LESS） technique is the latest technical innovation in laparoscopic surgery to undergo exponential development in urology. This study undertaken to illustrate our initial experience LESS radical prostatectomy （RP） and analyze early outcomes. Nineteen patients diagnosed with prostate cancer underwent LESS-RP in our institute. The patients were divided into two groups： conventional LESS and transurethral assistant LESS. Preoperative, perioperative, postoperative, pathologic, and functional outcomes data were assessed. With the help of a transurethral assistant, the mean operation and anastomosis time were decreased markedly. No focal positive margins were encountered. No prostate-specific antigen recurrence was detected 1 month postoperatively. Complete continence recovery （no pad） was observed in 32% of the patients at 1 month after the operation. No intraoperative and postoperative complications were reported, LESS-RP is a feasible and effective surgical procedure for treatment of prostate cancer. Moreover, transurethral assistant LESS could reduce the difficulty of LESS-RP and shorten the operation time.
基金The authors would like to express their gratitude to Prof.Kai Xu and his research and development team from Shanghai Jiao Tong University,Shanghai,China,for their invaluable technical support of this study.This research was funded by the National Key Research and Development Program of China(Grant No.2022YFB4700904 to Wang L)Research-Oriented Physicians'Innovative Transformation Training Program of Development Center,Shanghai Shenkang Hospital,Shanghai,China(Grant No.SHDC2022CRS010B to Tang S).
文摘Objective This prospective single-arm clinical trial aimed to evaluated the feasibility and safety of the application of the SHURUI system(Beijing Surgerii Technology Co.,Ltd.,Beijing,China),a novel purpose-built robotic system,in single-port robotic radical prostatectomy.Methods Sixteen patients diagnosed with prostate cancer were prospectively enrolled in and underwent robotic radical prostatectomy from October 2021 to August 2022 by the SHURUI single-port robotic surgical system.The demographic and baseline data,surgical,oncological,and functional outcomes as well as follow-up data were recorded.Results The mean operative time was 226.3(standard deviation[SD]52.0)min,and the mean console time was 183.4(SD 48.3)min,with the mean estimated blood loss of 116.3(SD 90.0)mL.The mean length of postoperative hospital stay was 4.50(SD 0.97)days.Two patients had postoperative complications(Clavien-Dindo Grade II),and both patients improved after conservative treatment.All patients’postoperative prostate-specific antigen levels decreased to below 0.2 ng/mL 1 month after discharge.The mean prostate-specific antigen level further decreased to a mean of 0.0219(SD 0.0641)ng/mL 6 months after surgery.Thirty days postoperatively,12 out of 16 patients reported using no more than one urinary pad per day,and all patients reported satisfactory urinary control without the need for pads 6 months after surgery.Conclusion The SHURUI system is safe and feasible in performing radical prostatectomy via both transperitoneal and extraperitoneal approaches.Tumor control and urinary continence were satisfying for patients enrolled in.The next phase involves conducting a large-scale,multicenter randomized controlled trial to thoroughly assess the effectiveness and safety of the new technology in a broader population.
文摘AIM To evaluate the feasibility,safety and peri-and postoperative outcomes of robotic single-site supracervical hysterectomy(RSSSH) for benign gynecologic disease.METHODS We report 3 patients who received RSSSH for adenomyosis of the uterus from November 2015 to April 2016.We evaluated the feasibility,safety and outcomes among these patients.RESULTS The mean surgical time was 244 min and the estimated blood loss was 216 mL,with no blood transfusion necessitated.The docking time was shortened gradually from 30 to 10 min.We spent 148 min on console operation.Manual morcel ation time was also short,ranging from 5 to 10 min.The mean hospital stay was 5 d.Lower VAS pain score was also noted.There is no complication during or after surgery.CONCLUSION RSSSH is feasible and safe,incurs less postoperative pain and gives good cosmetic appearance.The technique of inbag,manual morcellation can avoid tumor dissemination.
基金Supported by the Military Major Project for Clinical High-tech and Innovative Technology of China (2010gxjs057)the Municipal Hospitals’ Project for Emerging and Frontier Technology of Shanghai (SHDC12010115)the Project for the Key Discipline of Shanghai
文摘Background： Laparoendoscopic single-site surgery （LESS） may serve as a potential alternative to conventional laparoscopy and is developing quickly, but still in its infancy. The study is to present our two-year experience in transumbilical LESS simple nephrectomy （LESS-SN） for non-functioning kidney, in an effort to evaluate its feasibility, clinical outcomes and potential advantages. Methods： From December 2008 to December 2010, a total of 11 patients with body mass index （BMI）≤30 underwent transumbilical TriPortTM LESS-SN by a single experienced urologist at our institution. The indications for nephrectomy included nonfunctioning kidney associated with ureteropelvic junction stricture （n=l）, ureteral calculi （n=6）, tuberculosis （n=3）, and ureteral stricture （n=l）. Patient demographics perioperative and follow-up data were prospectively collected and analyzed. Results： Ten procedures were successfully completed with one patient converted to open surgery due to uncontrollable bleeding. The mean operative time was 189.2 （ranging 100-320 min） with an estimated blood loss of 204.5 （ranging 50-1 000 ml）. There were two complications of bleeding （1- intra-, 1- post-）. The mean hospitalization after surgery was 7.9 d （ranging 4-17 d） With a regular follow-up of 1, 6, 12, and 24 months after surgery, all patients remained symptom-free with an intra-umbilical scar. Conclusion： Transumbilical LESS simple nephrectomy for nonfunctioning kidney can be accomplished with favorable surgical outcomes and a superiority of cosmesis. However, cases with chronic inflammation are not suitable for initial up-take and should only be attempted by the very experienced laparoscopist.
基金Supported by the Municipal Hospitals' Project for Emerging and Frontier Technology of Shanghai(NO.SHDC12010115)Project for the Key Discipline of Shanghai
文摘Objective： To describe two cases of bilateral transumbilical laparoendoscopic single-site（LESS） surgeries in a single operative session and assess the safety, feasibility and efficacy. Methods： One patient underwent right ureterolithotomy and left varicocelectomy, and the patient was performed with right simple nephrectomy for nonfunctioning kidney due to ureteral calculus and left ureterolithotomy using a novel multichannel TriPortTM via a single 2-3 cm transumbilical incision Results： The right-side ureterolithotomy and left-side varicocelectomy were finished in 229 minutes, with a total estimated blood loss of 50 hal. The right-side simple nephrectomy and left-side ureterolithotomy in the other patient were finished in 340 minutes, with a total estimated blood loss of 100 ml. There were no major complications. At the latest follow-up, both patients remained symptom-free and there were no evidences of recurrence. Both of them were delighted for the single scarConclusion： Synchronous LESS urologic procedure via a single umbilical incision is technically feasible, safe and efficacious with a promising potential
基金Supported by the Military Major Project for Clinical High-tech and Innovative Technology of China(2010gxjs057)the Municipal Hospitals' Project for Emerging and Frontier Technology of Shanghai(SHDC12010115)the Project for the Key Discipline of Shanghai
文摘Objective:Nephron-sparing surgery(NSS) for small renal masses offers a similar functional and oncological outcome to that of radical surgery.Laparoendoscopic single-site surgery(LESS) emerges as an advanced alternative for reduced invasiveness and improves cosmesis;LESS is developing quickly and its indications have been expanded,but still in its infancy.The aim of this paper is to report our preliminary experience in transumbilical LESS partial nephrectomy(LESS-PN),so as to assess its utility, safety and efficacy.Methods:From August 2009 to October 2010,3 patients underwent transumbilical LESS-PN via a novel multi-channel TriPort by a single experienced urologist in our institution.Patient demographics,perioperative and follow-up data were prospectively collected and analyzed.Results:All the three procedures were successfully completed.A 5-mm ancillary trocar was utilized in all 3 cases.The mean operative duration was 226.3(210-254 min) with an estimated blood loss of 56.7 ml (20-100 ml).Mean warm ischemia time was 35.7 min(19-48 min).One patient was transfused due to postoperative bleeding. The recovery was uneventful and mean length of postoperative stay was 13 days(12-14 days).At the latest follow-up,all patients remained symptom-free and had normal renal function without evidence of recurrence,and they were delighted for a hidden transumbilical scar.Conclusion:Transumbilical LESS-PN is a feasible and safe procedure albeit extremely technically challenging.Surgical outcomes at a median follow-up of 2 years are promising,while currently it should be reserved for highly selected patients with favorable tumor anatomy and performed by a very experienced laparoscopic surgeon.
基金Supported by the Municipal Hospitals' Project for Emerging and Frontier Technology of Shanghai (SHDC12010115)the Chinese Military Major Project for Clinical High-tech and Innovative Technology (2010gxjs057)the Project of Key Discipline of Shanghai
文摘LaparoEndoscopic Single-site(LESS) renal surgery emerging as a potential alternative to conventional laparoscopy,is technically challenging and the major vascular anomaly may increase the risk of intraoperative haemorrhage.Herein,we present a case of right transumbilical LESS radical nephrectomy which was successfully performed in the presence of double inferior vena cava and duplicated the standard laparoscopic techniques.Most importantly,to bring such an aberrant vascular anatomy to the attention of laparoscopic,especially LESS surgeons with high resolution pictorial illustrations.
文摘Aim: To present our initial experience of applying laparoendoscopic single-site surgery (LESS) nephrolithotomy in the treatment of renal calculi. Methods: In August 2010 and April 2012, the LESS nephrolithotomy technique was applied to treat two patients with a renal calculus. One patient had a calculus measuring 5 × 3 cm, and the second patient's measured 3 × 3 cm. Both patients underwent general anesthesia. The operations were performed through a retroperitoneal approach with a single-port instrument inserted through the retroperitoneal incision. The standard laparoscopic retroperitoneal technique was performed, and the calculi were removed by incising the area of the thin renal cortex and the renal pelvis, respectively. The operating time, estimated blood loss, intraoperative complications, other complications, drainage time, and post-operative hospital stay were recorded. Results: Both procedures were completed successfully. No additional trocars were added. No conversion to standard laparoscopic or open surgery was needed. The operating times were 130 min and 120 min, and the estimated blood losses were 40 mL and 30 mL. There were no intraoperative complications. The wound drainage times were 3 d and 2 d, respectively and the post-operative hospital stays were 8 d and 7 d, respectively. There was no secondary bleeding or wound infection. Follow-up times were 2 years and 3 months, respectively. No incidence of hydronephrosis was recorded. Conclusions: LESS nephrolithotomy is safe and feasible for treating kidney calculi. It can be applied in patients with large renal calculi and regionally thin renal parenchyma.
文摘AIM:To review an evolution of laparoscopic surgery,there has been a growing interest in laparoendoscopic single-site surgery(LESS).METHODS:A comprehensive electronic literature search was conducted using PubM ed database to identify all publications relating to LESS-partial nephrectomy(PN).The research includes articles published from April 2008 to January 2014.We focused our attention only on articles in which were cited the single-site surgical technique(laparoscopic and robotic),tumour stage and grade,mean tumour size,intraoperative variables,blood loss and transfusion rate,length of postoperative stay and complication rates,Clavien classification,positive of surgical margins,pain assessment at discharge.RESULTS:A total of 9 studies were collected with 221patients included.The mean patients age was 62 years.The mean tumor size was 2.35 cm with a mean operative time of 181 min(range 111-270 min)and 58.3%were done by robot.The mean ischemia time was 23.6min.The 25.8%of patients underwent an unclamp LESS-PN.Mean estimated blood loss was 296 mL and median length of hospital stay was 4 d.The rate of severe post-operative complications(≥Clavien gradeⅢ)was 5.4%.Not all surgical series of LESS-PN or Robotic-LESS-PN shows conversion in Multiport Laparoscopic or Open Surgery.Regarding oncologic outcomes,surgical margins were positive 4%of patients(9/221),no distant or port-site metastases were recorded.CONCLUSION:LESS-PN and RLESS-PN are feasible and associated with reduced postoperative pain,shorter median hospital stay,shorter recovery time,and better cosmetic satisfaction without compromising surgical and oncological safety.
文摘Within the advance ports and instruments, laparoendoscopic single-site (LESS) surgery has been increasingly used among gynaecologic surgeons. In addition, advanced port systems have enabled to perform concomitant surgical procedures via transumbilical incision. However, combined surgical operations are rarely reported in the literature, particularly in gynaecology. This case report presents a 42-year-old woman who undergo concomitant LESS hysterectomy and nephrectomy due to deep infiltrating endometriosis (DIE) and end stage renal disease. The operation is performed in approximately 3 hours without any complications, and the patient is discharged on postoperative third day. This case demonstrates that complex concomitant operations even in a patient with DIE can be performed using a LESS surgical approach.
基金support from NationalNatural Science Foundation of China (grant nos.22368002 and 52300195)Young Elite Scientists SponsorshipProgram by Jiangxi Association for Science andTechnology (JXAST) (grant no.2023QT10)+5 种基金JiangxiProvincial Natural Science Foundation (grant nos.20224BAB203003 and 20232BAB203021)OpeningProject of Project of National Key Laboratory of UraniumResources Exploration-Mining and Nuclear RemoteSensing (grant no.2024QZ-KF-06)Jiangxi ProvinceKey Laboratory of Polymer Micro/Nano Manufacturingand Devices (grant no.PMND202204)Japan Scienceand Technology Agency (JST)- Exploratory Research forAdvanced Technology (ERATO) Yamauchi Materials Space-Tectonics Project (grant no.JPMJER2003)theAustralian Research Council (ARC) Laureate Fellowship(grant no.FL230100095)Science and TechnologyResearch Program of Chongqing Municipal EducationCommission (grant no.KJQN202201308)。
文摘Electrocatalytic reduction of nitrate(NO_(3)^(−))is a promising approach to achieving sustainable and green ammonia synthesis and environmental denitrification.Here,click chemistry is extended to fabricate dynamic singlesite metal catalysts for NO3−electroreduction.Specifically,Co^(2+)-coordinated molecular units are covalently clicked into a stable Th-metal–organic framework,confining and dispersing single-site metals that exhibit the asymmetrical Co–N2Cl2 coordination configuration.The obtained CoN2Cl2@Th-BPDC electrocatalyst achieves an outstanding ammonia production rate of 770.3μmol h^(−1) cm^(−2)(5135.3 mmol gcat^(−1) h^(−1))at−0.4 V versus RHE,which is approximately 25.7 times higher than that of the Haber–Bosch process(<200 mmol gcat^(−1) h^(−1))and outperforms the most recently reported electrocatalysts.Theoretical calculations reveal that single-site Co2+exhibits strong bidentate adsorption toward NO_(3)^(−)due to the suitable geometric space provided by the rotation of Co-coordinated Cl atoms(a dynamic feature),which promotes NO_(3)^(−)activation and decreases the reaction barrier,resulting in excellent catalytic activity.This study describes an innovative strategy for fabricating dynamic asymmetrical single-site metal electrocatalysts and may inspire new methodologies for the precise synthesis of advanced catalytic materials.
基金supported by the National Natural Science Foundation of China(No.22075099)Natural Science Foundation of Jilin Province(No.20180101291JC).
文摘The key challenge for scalable production of hydrogen from water lies in the rational design and preparation of high-performance and earth-abundant electrocatalysts to replace precious metal Pt and IrO_(2) for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Although atomic M-N-C materials have been extensively studied in heterogeneous catalysis field,the insufficient antioxidant capacity of carbonous substrates hinders their practical application in OER.Developing highly active and stable OER electrocatalysts is the key for electrochemical water splitting.This review presents feasible design strategies for fabricating carbon-free single-site catalysts and their applications in HER/OER and overall water splitting.The constitutive relationships between structure,composition,and catalytic performance for HER and OER are detailly discussed,providing ponderable insights into rationally constructing high-performance HER and OER electrocatalysts.The perspectives on the challenges and future research orientations in single-site catalysts for electrochemical water splitting are suggested.
基金the National Key Research and Development Program of China(Nos.2017 YFA0206500 and 2018YFA0209103)the National Natural Science Foundation of China(Nos.21832003,21773111,21972061,51571110,and 21573107).The numerical calculations have been done on the computing facilities in the High Performance Computing Center(HPCC)of Nanjing University.
文摘Metal-nitrogen-carbon materials are promising catalysts for CO2 electroreduction to CO. Herein, by taking the unique hierarchical carbon nanocages as the support, an advanced nickel-nitrogen-carbon single-site catalyst is conveniently prepared by pyrolyzing the mixture of NiCl2 and phenanthroline, which exhibits a Faradaic efficiency plateau of > 87% in a wide potential window of −0.6 – −1.0 V. Further S-doping by adding KSCN into the precursor much enhances the CO specific current density by 68%, up to 37.5 A·g−1 at −0.8 V, along with an improved CO Faradaic efficiency plateau of > 90%. Such an enhancement can be ascribed to the facilitated CO pathway and suppressed hydrogen evolution from thermodynamic viewpoint as well as the increased electroactive surface area and improved charge transfer fromkinetic viewpoint due to the S-doping. This study demonstrates a simple and effective approach to advanced electrocatalysts by synergetic modification of the porous carbon-based support and electronic structure of the active sites.
基金the National Key Research and Development Program of China(Nos.2021YFA1500900,2017YFA0206500,and 2018YFA0209103)the National Natural Science Foundation of China(Nos.21832003,21972061,and 52071174)+1 种基金the Natural Science Foundation of Jiangsu Province,Major Project(No.BK20212005)Nanjing University Innovation Program for PhD candidate(No.CXYJ21-38).
文摘The atomically dispersed Fe^(3+)sites of Fe-N-C single-site catalysts(SSCs)are demonstrated as the active sites for CO_(2)electroreduction(CO_(2)RR)to CO but suffer from the reduction to Fe^(2+)at~−0.5 V,accompanied by the drop of CO faradaic efficiency(FECO)and deterioration of partial current(JCO).Herein,we report the construction of F-doped Fe-N-C SSCs and the electron-withdrawing character of fluorine could stabilize Fe3+sites,which promotes the FECO from the volcano-like highest value(88.2%@−0.40 V)to the high plateau(>88.5%@−0.40-−0.60 V),with a much-increased JCO(from 3.24 to 11.23 mA·cm^(−2)).The enhancement is ascribed to the thermodynamically facilitated CO_(2)RR and suppressed competing hydrogen evolution reaction,as well as the kinetically increased electroactive surface area and improved charge transfer,due to the stabilized Fe^(3+)sites and enriched defects by fluorine doping.This finding provides an efficient strategy to enhance the CO_(2)RR performance of Fe-N-C SSCs by stabilizing Fe^(3+).
