Carbon dioxide(CO_(2) ) capture and conversion is the key route for the mitigation of the greenhouse effect and utilization of carbon sources to obtain value-added products or fuels.Much attention is paid to the devel...Carbon dioxide(CO_(2) ) capture and conversion is the key route for the mitigation of the greenhouse effect and utilization of carbon sources to obtain value-added products or fuels.Much attention is paid to the development of novel materials with high CO_(2) adsorption capacity and conversion rate.MXene is the graphene-like two-dimensional metal carbide/nitride/carbonitride owning favorable structure,morphology,high surface-bulk ratio,and physicochemical properties.Here,we review the CO_(2) capture,sensing,and conversion by MXene and MXene-based materials.Furthermore,the underlying mechanism involved the capture,sensing,and conversion of CO_(2) is summarized.This review would open a new horizon for CO_(2) valorization with high efficiency and promising widespread applications.展开更多
Inverse emulsion polymerization was employed to synthesize inverse emulsion Cd（Ⅱ） imprinted polymers （IEⅡ P）. The morphology and functional groups of IEⅡP were characterized by SEM,FTIR and TG. Static adsorptio...Inverse emulsion polymerization was employed to synthesize inverse emulsion Cd（Ⅱ） imprinted polymers （IEⅡ P）. The morphology and functional groups of IEⅡP were characterized by SEM,FTIR and TG. Static adsorption experiments and competitive adsorption test were used to evaluate the adsorption ability of IEⅡP. The adsorption capacity of polymers could reach 86.7 mg·g^-1 under the optimal adsorption conditions. The pseudo second order kinetic model and Langmuir isotherm model could be used to analyze the experimental data well. The adsorption process of IEⅡP was chemical adsorption process and monomolecular type. Thermodynamic parameters showed that the adsorption process was endothermic and could occur spontaneously. The selectivity coefficients k of Cd^2＋/v, Cd^2＋/Zn^2＋ and Cd^2＋/Cu^2＋ were 2.4998, 1.2437 and 4.6882, respectively. The proposed method provides a new thought for removing Cd（Ⅱ） in water samples.展开更多
p-Phenylenediamine(PPD)functionalized graphene oxide(GO)materials(PPDG)were prepared through a one-step solvothermal process and their application as supercapacitors(SCs)were studied.The PPD is not only as the spacers...p-Phenylenediamine(PPD)functionalized graphene oxide(GO)materials(PPDG)were prepared through a one-step solvothermal process and their application as supercapacitors(SCs)were studied.The PPD is not only as the spacers to prevent aggregating and restacking of the graphene sheets in the preparing process but also as nitrogen sources to obtain the nitrogen-doped graphene.The structures of PPDG were characterized by Fourier transformed infrared spectroscopy(FT-IR),X-ray diffraction spectroscopy(XRD),Raman spectroscopy and X-ray photoelectron spectroscopy(XPS)and the results show that the nitrogen-doped graphene was achieved with nitrogen content as high as 10.85 at.%.The field emission scanning electron microscopy(FE-SEM)and high resolution transmission electron microscopy(HR-TEM)have confirmed that the morphologies of PPDG were loose layered with less aggregation,indicating that PPD molecules,as spacers,effectively prevent the graphene sheets from restacking during the solvothermal reaction.The special loose textures make PPDG materials exhibit excellent electrochemical performance for symmetric SCs with superior specific capacitance(313 F/g at 0.1 A/g),rate capability and cycling stability.The present synthesis method is convenient and may have potential applications as ultrahigh performance SCs.展开更多
Returning crop straw into the soil is an important practice to balance biogenic and bioavailable silicon(Si)pool in paddy,which is crucial for the healthy growth of rice.However,owing to little knowledge about soil mi...Returning crop straw into the soil is an important practice to balance biogenic and bioavailable silicon(Si)pool in paddy,which is crucial for the healthy growth of rice.However,owing to little knowledge about soil microbial communities responsible for straw degradation,how straw return affects Si bioavailability,its uptake,and rice yield remains elusive.Herein,we investigate the change of soil Si fractions and microbial community in a 39-year-old paddy field amended by a long-term straw return.Results show that rice straw return significantly increased soil bioavailable Si and rice yield from 29.9%to 61.6%and from 14.5%to 23.6%,respectively,when compared to NPK fertilization alone.Straw return significantly altered soil microbial community abundance.Acidobacteria was positively and significantly related to amorphous Si,while Rokubacteria at phylum level,Deltaproteobacteria,and Holophagae at class level was negatively and significantly related to organic matter adsorbed and Fe/Mn-oxide-combined Si in soils.Redundancy analysis of their correlations further demonstrated that Si status significantly explained 12%of soil bacterial community variation.These findings suggest that soil bacteria community and diversity interact with Si mobility by altering its transformation,thus resulting in the balance of various nutrient sources to drive biological Si cycle in agroecosystem.展开更多
Design and synthesis of efficient photocatalysts for hydrogen production via water splitting are of great importance from both theoretical and practical viewpoints. Many metal-based semiconductors have been explored f...Design and synthesis of efficient photocatalysts for hydrogen production via water splitting are of great importance from both theoretical and practical viewpoints. Many metal-based semiconductors have been explored for this purpose in recent decades. Here, for the first time, an entirely carbon-based material, bulk three-dimensionally cross-linked graphene （3DG）, has been developed as a photocatalyst for hydrogen production. It exhibits a remarkable hydrogen production rate of 270 μmol-h-l.g-t under full-spectrum light via a hot/free electron emission mechanism. Furthermore, when combined with the widely used semiconductor TiO2 to form a TiO2/3DG composite, it appears to become a more efficient hydrogen production photocatalyst. The composite achieves a production rate of 1,205 bimol-h μg-t under ultraviolet-visible （UV-vis） light and a 7.2% apparent quantum efficiency at 350 nm due to the strong synergetic effects between TiO2 and 3DG.展开更多
Surface engineering has been found to be an efficient strategy to boost the catalytic performance of noble-metal-based nanocatalysts.In this work,a small amount of P was doped to the surface of PtNi concave cube(P-PtN...Surface engineering has been found to be an efficient strategy to boost the catalytic performance of noble-metal-based nanocatalysts.In this work,a small amount of P was doped to the surface of PtNi concave cube(P-PtNi CNC).Interestingly,the P-PtNi CNC nanocatalyst shows an enhanced methanol oxidation reaction(MOR)performance with achieving 8.19 times of specific activity than that of comercial Pt/C.The electrochemical in situ Fourier transform infrared spectroscopy(FTIR)results reveal that the surface P doping promotes the adsorption energy of OH,enhancing the resistance against CO poisoning.Therefore,the intermediate adsorbed CO(COads)reacted with adsorbed OH(OHads)through the Langmuir–Hinshelwood(LH)mechanism to generate CO_(2)and release surface active sites for further adsorption.This work provides a promising strategy via the incorporation of non-metallic elements into the PtNi alloys bounded with high-index facets(HIFs)as efficient fuel cell catalysts.展开更多
Dissolution of lithium cobalt oxide(LCO)is the key step for the recovery of valuable metals(e.g.,Co and Li)from spent LCO-based lithium-ion batteries(LIBs).However,the dissolution process of LCO either needs toxic sol...Dissolution of lithium cobalt oxide(LCO)is the key step for the recovery of valuable metals(e.g.,Co and Li)from spent LCO-based lithium-ion batteries(LIBs).However,the dissolution process of LCO either needs toxic solvents,and high temperature,or shows low efficiency.Deep eutectic solvents(DESs)are potential green solvents to dissolve LCO.Here,DESs with polyethylene glycol(PEG)as hydrogen bond acceptor and ascorbic acid(AA)as hydrogen bond donor are found to dissolve LCO with 84.2%Co leaching efficiency at 80℃ and 72 h,which is higher than that from the reported references by common DESs.Furthermore,both DESs components(i.e.,PEG and AA)are cheap,biodegradable,and biocompatible.AA could be easily and abundantly extracted from natural fruits or vegetables.It provides a new guide for the green,mild,and efficient dissolution of LCO aiming at sustainable recovery of spent LIBs.展开更多
Fe-modified biochar(FB)and co-using Chinese milk vetch and rice straw(MR)are two effective ways for mitigating the cadmium(Cd)contamination in paddy fields in southern China.Nevertheless,the effects of FB combined wit...Fe-modified biochar(FB)and co-using Chinese milk vetch and rice straw(MR)are two effective ways for mitigating the cadmium(Cd)contamination in paddy fields in southern China.Nevertheless,the effects of FB combined with MR on Cd passivation mechanism remain unclear.In the current study,the strengthening effects of FB induced by MR were found and the mechanisms of the extracted dissolved organic matter(DOM)from the co-decomposition of MR on Cd alleviation were investigated through pot experiment and adsorption experiment.Pot experiment demonstrated that co-incorporating FB and MR decreased available Cd by 23.1%and increased iron plaque concentration by 11.8%,resulting in a 34.7%reduction in Cd concentrations in brown rice compared with addition of FB.Furthermore,co-using FB and MR improved available nutrients in the soil.The molecular characteristics of DOM derived from the decomposition of MR(DOM-MR)were analyzed by fluorescence excitation emission matrix spectroscopy-parallel factor analysis(EEM-PARAFAC)and Fourier transform-ion cyclotron resonance mass spectrometry(FT-ICR MS).Results showed that lignin/carboxylic-rich alicyclic molecules and protein/amino sugar were the main compounds,potentially involved in the Cd binding.Adsorption experiments revealed that the addition of DOM-MR improved the functional groups,specific surface area,and negative charges of FB,inducing the strengthening of both physisorption and chemisorption of Cd(II).The maximum adsorption capacity of Fe-modified biochar after adding DOM-MR was 634 mg g−1,1.30 times that without the addition of DOM-MR.This study suggested that co-incorporating MR,and FB could serve as an innovative practice for simultaneous Cd remediation and soil fertilization in Cd-polluted paddy fields.It also provided valuable insights and basis that DOM-MR could optimize the performances of Fe-modified biochar and enhance its potential for Cd immobilization.展开更多
The possible practical limits for the specific surface area and capacitance performance of bulk sp^2 carbon materials were investigated experimentally and theoretically using a variety of carbon materials. We find the...The possible practical limits for the specific surface area and capacitance performance of bulk sp^2 carbon materials were investigated experimentally and theoretically using a variety of carbon materials. We find the limit for the specific surface area to be 3500–3700 m^2 g^(-1), and based on this, the corresponding best capacitance was predicted for various electrolyte systems. A model using an effective ionic diameter for the electrolyte ions was proposed and used to calculate the theoretical capacitance. A linear dependence of experimental capacitance versus effective specific surface area of various sp^2 carbon materials was obtained for all studied ionic liquid, organic and aqueous electrolyte systems. Furthermore, excellent agreement between the theoretical and experimental capacitance was observed for all the tested sp^2 carbon materials in these electrolyte systems, indicating that this model can be applied widely in the evaluation of various carbon materials for supercapacitors.展开更多
基金Natural Science Foundation of Hebei Province (B2019408018, E2020048004)the Fundamental Research Funds for the Universities in Hebei Province (JYQ201902, JYT201901)+4 种基金Program for the Top Young Talents of Higher Learning Institutions of Hebei Province (BJ2020047)College Students’ Innovation and Entrepreneurship Training Program Project Fund of Langfang Normal University (202010100001, S202010100011)National Natural Science Foundation of China (21773307)Hebei Higher Education Teaching Reform Research and Practice Project (2019GJJG357)Research Project of Langfang Teachers University (LSLB201701) for financial support。
文摘Carbon dioxide(CO_(2) ) capture and conversion is the key route for the mitigation of the greenhouse effect and utilization of carbon sources to obtain value-added products or fuels.Much attention is paid to the development of novel materials with high CO_(2) adsorption capacity and conversion rate.MXene is the graphene-like two-dimensional metal carbide/nitride/carbonitride owning favorable structure,morphology,high surface-bulk ratio,and physicochemical properties.Here,we review the CO_(2) capture,sensing,and conversion by MXene and MXene-based materials.Furthermore,the underlying mechanism involved the capture,sensing,and conversion of CO_(2) is summarized.This review would open a new horizon for CO_(2) valorization with high efficiency and promising widespread applications.
基金Supported by the National Natural Science Foundation of China(21276174)the Natural Science Foundation of Shanxi Province(2013011040-1)
文摘Inverse emulsion polymerization was employed to synthesize inverse emulsion Cd（Ⅱ） imprinted polymers （IEⅡ P）. The morphology and functional groups of IEⅡP were characterized by SEM,FTIR and TG. Static adsorption experiments and competitive adsorption test were used to evaluate the adsorption ability of IEⅡP. The adsorption capacity of polymers could reach 86.7 mg·g^-1 under the optimal adsorption conditions. The pseudo second order kinetic model and Langmuir isotherm model could be used to analyze the experimental data well. The adsorption process of IEⅡP was chemical adsorption process and monomolecular type. Thermodynamic parameters showed that the adsorption process was endothermic and could occur spontaneously. The selectivity coefficients k of Cd^2＋/v, Cd^2＋/Zn^2＋ and Cd^2＋/Cu^2＋ were 2.4998, 1.2437 and 4.6882, respectively. The proposed method provides a new thought for removing Cd（Ⅱ） in water samples.
基金supported by the Ministry of Science and Technology (2012CB933401,2014CB643502)the National Natural Science Foundation of China (51273093,21374050,51373078)+2 种基金Natural Science Foundation of Tianjin (10ZCGHHZ00600)the Synergetic Innovation Center of Chemical Science and Engineering (Tianjin),Science and Technology Research Project of Higher Education of Hebei Province (z2012064)Science Research Project of Langfang Teachers College (LSZQ200908)
文摘p-Phenylenediamine(PPD)functionalized graphene oxide(GO)materials(PPDG)were prepared through a one-step solvothermal process and their application as supercapacitors(SCs)were studied.The PPD is not only as the spacers to prevent aggregating and restacking of the graphene sheets in the preparing process but also as nitrogen sources to obtain the nitrogen-doped graphene.The structures of PPDG were characterized by Fourier transformed infrared spectroscopy(FT-IR),X-ray diffraction spectroscopy(XRD),Raman spectroscopy and X-ray photoelectron spectroscopy(XPS)and the results show that the nitrogen-doped graphene was achieved with nitrogen content as high as 10.85 at.%.The field emission scanning electron microscopy(FE-SEM)and high resolution transmission electron microscopy(HR-TEM)have confirmed that the morphologies of PPDG were loose layered with less aggregation,indicating that PPD molecules,as spacers,effectively prevent the graphene sheets from restacking during the solvothermal reaction.The special loose textures make PPDG materials exhibit excellent electrochemical performance for symmetric SCs with superior specific capacitance(313 F/g at 0.1 A/g),rate capability and cycling stability.The present synthesis method is convenient and may have potential applications as ultrahigh performance SCs.
基金Fundamental Research Funds for Central Non-profit Scientific Institution(Nos.1610132019011,1610132020012)the National Key Research and Development Program of China(Nos.2016YFD0800707,2016YFD0200109).
文摘Returning crop straw into the soil is an important practice to balance biogenic and bioavailable silicon(Si)pool in paddy,which is crucial for the healthy growth of rice.However,owing to little knowledge about soil microbial communities responsible for straw degradation,how straw return affects Si bioavailability,its uptake,and rice yield remains elusive.Herein,we investigate the change of soil Si fractions and microbial community in a 39-year-old paddy field amended by a long-term straw return.Results show that rice straw return significantly increased soil bioavailable Si and rice yield from 29.9%to 61.6%and from 14.5%to 23.6%,respectively,when compared to NPK fertilization alone.Straw return significantly altered soil microbial community abundance.Acidobacteria was positively and significantly related to amorphous Si,while Rokubacteria at phylum level,Deltaproteobacteria,and Holophagae at class level was negatively and significantly related to organic matter adsorbed and Fe/Mn-oxide-combined Si in soils.Redundancy analysis of their correlations further demonstrated that Si status significantly explained 12%of soil bacterial community variation.These findings suggest that soil bacteria community and diversity interact with Si mobility by altering its transformation,thus resulting in the balance of various nutrient sources to drive biological Si cycle in agroecosystem.
文摘Design and synthesis of efficient photocatalysts for hydrogen production via water splitting are of great importance from both theoretical and practical viewpoints. Many metal-based semiconductors have been explored for this purpose in recent decades. Here, for the first time, an entirely carbon-based material, bulk three-dimensionally cross-linked graphene （3DG）, has been developed as a photocatalyst for hydrogen production. It exhibits a remarkable hydrogen production rate of 270 μmol-h-l.g-t under full-spectrum light via a hot/free electron emission mechanism. Furthermore, when combined with the widely used semiconductor TiO2 to form a TiO2/3DG composite, it appears to become a more efficient hydrogen production photocatalyst. The composite achieves a production rate of 1,205 bimol-h μg-t under ultraviolet-visible （UV-vis） light and a 7.2% apparent quantum efficiency at 350 nm due to the strong synergetic effects between TiO2 and 3DG.
基金the National Natural Science Foundation of China(No.21573286)the Natural Science Foundation of Hebei Province of China(No.E2020408004)the Funded by Science and Technology Project of Hebei Education Department(No.QN2021124).
文摘Surface engineering has been found to be an efficient strategy to boost the catalytic performance of noble-metal-based nanocatalysts.In this work,a small amount of P was doped to the surface of PtNi concave cube(P-PtNi CNC).Interestingly,the P-PtNi CNC nanocatalyst shows an enhanced methanol oxidation reaction(MOR)performance with achieving 8.19 times of specific activity than that of comercial Pt/C.The electrochemical in situ Fourier transform infrared spectroscopy(FTIR)results reveal that the surface P doping promotes the adsorption energy of OH,enhancing the resistance against CO poisoning.Therefore,the intermediate adsorbed CO(COads)reacted with adsorbed OH(OHads)through the Langmuir–Hinshelwood(LH)mechanism to generate CO_(2)and release surface active sites for further adsorption.This work provides a promising strategy via the incorporation of non-metallic elements into the PtNi alloys bounded with high-index facets(HIFs)as efficient fuel cell catalysts.
基金This work was supported by the National Natural Science Foundation of China(22103030)Open Fund of Hebei Biomass Carbon Materials and Application Technology Innovation Center(SG2021003)Special Project for the Cultivation of Scientific and Technological Innovation Ability of College and Middle School Students in Hebei Province(22E50480D).
文摘Dissolution of lithium cobalt oxide(LCO)is the key step for the recovery of valuable metals(e.g.,Co and Li)from spent LCO-based lithium-ion batteries(LIBs).However,the dissolution process of LCO either needs toxic solvents,and high temperature,or shows low efficiency.Deep eutectic solvents(DESs)are potential green solvents to dissolve LCO.Here,DESs with polyethylene glycol(PEG)as hydrogen bond acceptor and ascorbic acid(AA)as hydrogen bond donor are found to dissolve LCO with 84.2%Co leaching efficiency at 80℃ and 72 h,which is higher than that from the reported references by common DESs.Furthermore,both DESs components(i.e.,PEG and AA)are cheap,biodegradable,and biocompatible.AA could be easily and abundantly extracted from natural fruits or vegetables.It provides a new guide for the green,mild,and efficient dissolution of LCO aiming at sustainable recovery of spent LIBs.
基金funded by the National Key Research and Development Program of China(2021YFD1700200)the earmarked fund for CARS‐Green manure(CARS-22)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(ASTIP).
文摘Fe-modified biochar(FB)and co-using Chinese milk vetch and rice straw(MR)are two effective ways for mitigating the cadmium(Cd)contamination in paddy fields in southern China.Nevertheless,the effects of FB combined with MR on Cd passivation mechanism remain unclear.In the current study,the strengthening effects of FB induced by MR were found and the mechanisms of the extracted dissolved organic matter(DOM)from the co-decomposition of MR on Cd alleviation were investigated through pot experiment and adsorption experiment.Pot experiment demonstrated that co-incorporating FB and MR decreased available Cd by 23.1%and increased iron plaque concentration by 11.8%,resulting in a 34.7%reduction in Cd concentrations in brown rice compared with addition of FB.Furthermore,co-using FB and MR improved available nutrients in the soil.The molecular characteristics of DOM derived from the decomposition of MR(DOM-MR)were analyzed by fluorescence excitation emission matrix spectroscopy-parallel factor analysis(EEM-PARAFAC)and Fourier transform-ion cyclotron resonance mass spectrometry(FT-ICR MS).Results showed that lignin/carboxylic-rich alicyclic molecules and protein/amino sugar were the main compounds,potentially involved in the Cd binding.Adsorption experiments revealed that the addition of DOM-MR improved the functional groups,specific surface area,and negative charges of FB,inducing the strengthening of both physisorption and chemisorption of Cd(II).The maximum adsorption capacity of Fe-modified biochar after adding DOM-MR was 634 mg g−1,1.30 times that without the addition of DOM-MR.This study suggested that co-incorporating MR,and FB could serve as an innovative practice for simultaneous Cd remediation and soil fertilization in Cd-polluted paddy fields.It also provided valuable insights and basis that DOM-MR could optimize the performances of Fe-modified biochar and enhance its potential for Cd immobilization.
基金supported by the National Basic Research Program of China(2012CB933401)the National Natural Science Foundation of China(51472124+3 种基金5127309321374050)the Natural Science Foundation of Tianjin(13RCGFGX01121)Science Research Project of Langfang Teachers University(LSLB201401)
文摘The possible practical limits for the specific surface area and capacitance performance of bulk sp^2 carbon materials were investigated experimentally and theoretically using a variety of carbon materials. We find the limit for the specific surface area to be 3500–3700 m^2 g^(-1), and based on this, the corresponding best capacitance was predicted for various electrolyte systems. A model using an effective ionic diameter for the electrolyte ions was proposed and used to calculate the theoretical capacitance. A linear dependence of experimental capacitance versus effective specific surface area of various sp^2 carbon materials was obtained for all studied ionic liquid, organic and aqueous electrolyte systems. Furthermore, excellent agreement between the theoretical and experimental capacitance was observed for all the tested sp^2 carbon materials in these electrolyte systems, indicating that this model can be applied widely in the evaluation of various carbon materials for supercapacitors.
