Solution-processed Cu(In,Ga)Se_(2)(CIGS) solar cells suffer from serious carrier recombination and power conversion efficiency(PCE) loss because of the poor film properties and easy formation of defects.Herein, we pro...Solution-processed Cu(In,Ga)Se_(2)(CIGS) solar cells suffer from serious carrier recombination and power conversion efficiency(PCE) loss because of the poor film properties and easy formation of defects.Herein, we propose Ag&Se co-selenization strategy to enhance the crystallization and passivate harmful defects of the CIGS films. The formation of Ag-Se phase during the selenization process enables the formation of large grains and suppresses the deep level defects. It is found that Ag doping can enlarge the depletion region width, lower the Urbach energy and prolong the carrier lifetime. As a result, a champion solution-processed CIGS solar cell presents a high efficiency of 16.48% with the highly improved opencircuit voltage(VOC) of 662 m V and fill factor(FF) of 75.8%. This work provides an efficient strategy to prepare high quality solution-processed CIGS films for high-performance CIGS solar cells.展开更多
Different from full-Heusler compounds,four vacancies in the face-centered cubic crystal structure provide extra sites for enhancing the thermoelectric properties of half-Heusler compounds(HHs).Herein,excess Ag is intr...Different from full-Heusler compounds,four vacancies in the face-centered cubic crystal structure provide extra sites for enhancing the thermoelectric properties of half-Heusler compounds(HHs).Herein,excess Ag is introduced to the Ni-site vacancies of ZrNiSn to optimize thermoelectric properties.The ZrNiAg_(x)Sn(x=0,0.01,0.02,and 0.03)samples were synthesized by levitation melting and spark plasma sintering.Remarkably,the introduction of excess Ag significantly improves the Seebeck coefficient of ZrNiAg_(0.01)Sn,and a peak power factor of~4.52 mW/(m K^(2))is achieved in ZrNiAg_(0.01)Sn at 923 K,which is enhanced by 22.8%than that of pristine ZrNiSn.As a result,the figure of merit zT of pristine ZrNiSn is enhanced from~0.60 to~0.72 of ZrNiAg_(0.01)Sn at 923 K.Additionally,grain refinement effectively increases the Vickers hardness of ZrNiAg_(0.01)Sn,which is enhanced by 32.8%than that of pristine ZrNiSn.These results demonstrate a viable doping strategy for designing ZrNiSn-based HHs with excellent thermoelectric and mechanical properties.展开更多
Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg va...Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg vacancies easily leads to deterioration of electrical properties,especially for p-type Mg_(3)Bi_(2) flm.And the optimization of thermal conductivity of the Mg_(3)Bi_(2)-based flms is barely investigated.In this work,we demonstrate the improved thermoelectric performances of p-type Mg_(3)Bi_(2) through Ag doping by magnetron sputtering.This doping successfully reduces the hole concentration and broadens the band gap of Mg_(3)Bi_(2),thus resulting in a peak power factor of 442μW m−1 K−2 at 525 K.At the same time,Ag doping-induced fuctuations in mass and microscopic strain efectively enhanced the phonon scattering to reduce the lattice thermal conductivity.Consequently,a maximum thermoelectric fgure of merit of 0.22 is achieved at 525 K.Its near-roomtemperature thermoelectric performances demonstrate superior performance compared to many Mg_(3)Bi_(2)-based flms.To further evaluate its potential for thermoelectric power generation,we fabricated a thermoelectric device using Ag-doped Mg_(3)Bi_(2) flms,which achieved a power density of 864μW cm⁻2 at 35 K temperature diference.This study presents an efective strategy for the advancement of Mg_(3)Bi_(2)-based flms for application in micro-thermoelectric devices.展开更多
Using the spray pyrolysis process,the work shows the production of pristine and 6%Ag-doped methylammonium lead iodide bromide(MAPbI2Br)film.Through X-ray diffraction analysis,it was found that Ag doping led to a signi...Using the spray pyrolysis process,the work shows the production of pristine and 6%Ag-doped methylammonium lead iodide bromide(MAPbI2Br)film.Through X-ray diffraction analysis,it was found that Ag doping led to a significant increase in grain size to 29.64 nm,alongside reductions in dislocation line density to 5.39×1014 m−2 and d-spacing to 3.18Å,while maintaining the native cubic crystal structure of MAPbI2Br.This research demonstrates a reduction in deep-level trap states with Ag doping,along with a significant narrowing of the band gap to 1.91 eV in the 6%Ag-doped MAPbI2Br.Moreover,the refractive index and extinction coefficient increased to 2.54 and 2.13,respectively.Regarding solar cell performance,all cells demonstrated encouraging outcomes;still,the 6%Ag-doped cell distinguished itself with a fill factor of 0.82,an open-circuit voltage of 1.07 V,an outstanding short-circuit current density of 11.31 mA/cm²,and an efficiency of 10.03%.These results highlight the effectiveness of Ag doping in improving perovskite solar cell technology,marking a notable progress in this field.展开更多
Self-trapped excitons are prevalent in metal halide perovskites(MHPs)characterized by soft lattices and strong exciton-phonon coupling,emitting photons with broadband emission and large Stokes shifts,rendering them pa...Self-trapped excitons are prevalent in metal halide perovskites(MHPs)characterized by soft lattices and strong exciton-phonon coupling,emitting photons with broadband emission and large Stokes shifts,rendering them particularly well-suited for applications in light-emitting diodes.But their photoluminescence quantum yields(PLQY)are limited by both high exciton binding energy and halogen-vacancy-associated non-radiative recombination.Here,we show that PLQY could be enhanced by a factor of 5.6 from 16%to 89%through doping trace Ag into Cs_(2)NaBiCl_(6)double perovskites,superior to those of previous Cs_(2)NaBiCl_(6)-based emitters.Experimental and theoretical studies reveal that trace Ag-initiated covalent interactions could reduce the exciton binding energy by 0.12 eV due to local symmetry breaking,thus improving the photoexcitation process.Also,this covalent interaction could passivate Cl vacancy defects,suppressing non-radiative recombination.Therefore,Cs2NaBiCl6:0.7%Ag^(+)could accumulate active self-trapped excitons to obtain high PLQY.Assembly of near-infrared light-emitting diodes using Cs_(2)NaBiCl_(6):0.7%Ag^(+)illustrates their valuable applications in nondestructive spectral analysis and night vision illumination.This work shows an effective strategy of improving photoemission of MHPs with high PLQY for advanced optoelectronic applications.展开更多
The zinc indium sulfide(ZnIn_(2)S_(4))semiconductors have garnered significant interest in photocatalysis due to their environmentally friendly characteristics,appropriate bandgap,and high absorption coefficient.Howev...The zinc indium sulfide(ZnIn_(2)S_(4))semiconductors have garnered significant interest in photocatalysis due to their environmentally friendly characteristics,appropriate bandgap,and high absorption coefficient.However,the exploration of advanced strategies to realize the effective and tailored doping still poses significant challenges in enhancing hydrogen evolution performance.In this work,a mild cation exchange strategy is reported to incorporate Ag cations into flower-like ZnIn_(2)S_(4) microspheres,enabling the selective replacement of Zn atoms by Ag.Remarkably,the as-fabricated Ag-ZnIn_(2)S_(4) exhibited exceptional photocatalytic hydrogen production performance,achieving a rate of 8098μmol·g^(−1)·h^(−1) under visible light irradiation.This is 4 times than that of pristine ZnIn_(2)S_(4)(2002μmol·g^(−1)·h^(−1)),and stands as the highest one among metal-doped-ZnIn_(2)S_(4) photocatalysts ever reported.Along with the theoretical calculations,it has been confirmed that the enhanced photocatalytic hydrogen generation behavior can primarily be attributed to the synergistic effect with improved light absorption,reduced adsorption energy,increased active sites and optimized charge carrier transfer,induced by the cation exchange with Ag in ZnIn_(2)S_(4).This work might provide some valuable insights on the design and development of highly efficient visible light driven photocatalysts for water splitting applications.展开更多
Antiperovskite compounds Mn3Ag1-xCoxN （x =0.2, 0.5 and 0.8） are synthesized and the doping effect of the magnetic element Co at the Ag site is investigated. The crystal structure is not changed by the introduction o...Antiperovskite compounds Mn3Ag1-xCoxN （x =0.2, 0.5 and 0.8） are synthesized and the doping effect of the magnetic element Co at the Ag site is investigated. The crystal structure is not changed by the introduction of Co. However, with the increase of the content of Co, the spin reorientation gradually disappears and the antiferromagnetic transition changes to the ferromagnetic transition at the elevated temperature when x = 0.8. In addition, all of the magnetic phase transitions at the elevated temperature are always accompanied by the abnormal thermal expansion behaviors and an entropy change. Moreover, when x = 0.8, the coefficient of linear expansion is -1.89 × 10^-6 K^-1 （290-310K, △T =20 K）, which is generally considered as the low thermal expansion.展开更多
Polycrystalline samples of Lal-x（Srl-yAgy）x MnO3 （y = 0.0, 0.2, 0.4, 0.6, 1.0） were prepared by the solid-state reaction method. The temperature stability of magnetoresistance and magnetoresistance enhancement in ...Polycrystalline samples of Lal-x（Srl-yAgy）x MnO3 （y = 0.0, 0.2, 0.4, 0.6, 1.0） were prepared by the solid-state reaction method. The temperature stability of magnetoresistance and magnetoresistance enhancement in Lal_x（Srl_yAgy）~MnO3 system with both univalent and bivalent elements doped at A site and with unchanged value of Mn~＋/Mn4＋ ratio were explored through the measurements of X-ray diffraction patterns, magnetiza- tion-temperature （M-T） curves, resistivity-temperature （p-T） curves and magnetoresistance-temperature （MR-T） curves. The results are as follows： there are two peaks in the p-T curves of the samples with Ag doping, one is caused by resistance change during the paramagnetism- ferromagnetism transition, and the other is from boundary- dependent scattering of conduction electrons on the boundaries of grains. The peak value of MR increases with increasing Ag doping content, and it increases from 8.2 % for y ---- 0.2 to 29.6 % for y ---- 1.0 under the magnetic field of B = 0.8 T; MR remains a constant of 12 % in the temperature range of 218-168 K for the sample with y = 1.0, and the temperature stability of MR is in favor of the practical application of MR.展开更多
The AgCuInGa alloy precursors with different Ag concentrations are fabricated by sputtering an Ag target and a CuInGa target.The precursors are selenized in the H_(2)Se-containing atmosphere to prepare(Ag,Cu)(In,Ga)Se...The AgCuInGa alloy precursors with different Ag concentrations are fabricated by sputtering an Ag target and a CuInGa target.The precursors are selenized in the H_(2)Se-containing atmosphere to prepare(Ag,Cu)(In,Ga)Se_(2)(ACIGS)absorbers.The beneficial effects of Ag doping are demonstrated and their mechanism is explained.It is found that Ag doping significantly improves the films crystallinity.This is believed to be due to the lower melting point of chalcopyrite phase obtained by the Ag doping.This leads to a higher migration ability of the atoms that in turn promotes grain boundary migration and improves the film crystallinity.The Ga enrichment at the interface between the absorber and the back electrode is also alleviated during the selenization annealing.It is found that Ag doping within a specific range can passivate the band tail and improve the quality of the films.Therefore,carrier recombination is reduced and carrier transport is improved.The negative effects of excessive Ag are also demonstrated and their origin is revealed.Because the atomic size of Ag is different from that of Cu,for the Ag/(Ag+Cu)ratio(AAC)≥0.030,lattice distortion is aggravated,and significant micro-strain appears.The atomic radius of Ag is close to those of In and Ga,so that the continued increase in AAC will give rise to the Ag;or Ag;defects.Both the structural and compositional defects degrade the quality of the absorbers and the device performance.An excellent absorber can be obtained at AAC of 0.015.展开更多
Alloying with Se is proved to be feasible to suppress the lattice thermal conductivity(κL)of tellurium by introducing multidimensional lattice defects.However,extra ionization impurity centers induced by Se alloying ...Alloying with Se is proved to be feasible to suppress the lattice thermal conductivity(κL)of tellurium by introducing multidimensional lattice defects.However,extra ionization impurity centers induced by Se alloying are harmful to the electric transport properties of the matrix.In this paper,we propose that the incorporation of Ag could successfully compensate the lost carrier mobility(μH)due to Se alloying through the regulation of microstructure,resulting in the higher power factor(PF)than that of samples without Ag.After composition optimization,theκLdecreased from 1.29 W m^(-1)K^(-1) of Te_(0.99)Sb_(0.01) to 1.05 W m^(-1)K^(-1) of Te_(0.94)Ag_(0.02)Se_(0.03)Sb_(0.01) at 350 K,while the PF remained unchanged or even slightly increased.Benefit from the synergistic effect of carrier mobility compensation and phonon scattering,a maximum z T of 0.91 at 573 K and an average z T of 0.57(between 298 and 573 K)are achieved in Te_(0.94)Ag_(0.02)Se_(0.03)Sb_(0.01).This work presents a new strategy for decoupling the thermal and electric parameters of Te-based thermoelectric materials.展开更多
A two-step method is adopted to synthesize Ag-doped ZnO nanorods. A ZnO seed layer is first prepared on a glass substrate by thermal decomposition of zinc acetate. Ag-doped ZnO nanorods are then assembled on the ZnO s...A two-step method is adopted to synthesize Ag-doped ZnO nanorods. A ZnO seed layer is first prepared on a glass substrate by thermal decomposition of zinc acetate. Ag-doped ZnO nanorods are then assembled on the ZnO seed layer using the hydrothermal method. The influences of the molar percentage of Ag ions to Zn ions （RAg/zn） on the structural and optical properties of the ZnO nanorods obtained are carefully studied using X-ray diffractometry, scanning electron microscopy and spectrophotometry. Results indicate that Ag ions enter into the crystal lattice through the substitution of Zn ions. The （002） c-axis-preferred orientation of the ZnO nanorods decreases as RAg/Zn increases. At RAg/Zn 〉 1.0%, ZnO nanorods lose their c-axis-preferred orientation and generate Ag precipitates from the ZnO crystal lattice. The average transmissivity in the visible region first increases and then decreases as RAg/Zn increases. The absorption edge is first blue shifted and then red shifted. The influence of Ag doping on the average head face, and axial dimensions of the ZnO nanorods may be optimized to improve the average transmissivity at RAg/Zn 〈 1.0%.展开更多
In_4Se_3-based materials are noticeable n-type thermoelectric materials because of lead-free and intrinsically low lattice thermal conductivity,but the In4Se_3-δ crystals（with Se-deficiency,δ） suffer strong anisot...In_4Se_3-based materials are noticeable n-type thermoelectric materials because of lead-free and intrinsically low lattice thermal conductivity,but the In4Se_3-δ crystals（with Se-deficiency,δ） suffer strong anisotropy and cleavage habit. Thus the researches on polycrystalline In_4Se_3-based materials are of great importance. Herein,we experimentally and theoretically investigated the thermoelectric properties of In_（4-x）Se_（2.95）Ag_x polycrystalline compounds. Ag occupying the intercalation or In4 site is energetically most favorable in light of the density functional theory calculation. The maximum solubility of Ag（x_m） is very low（xm 〈 0.03） and the experimental result indicates that the electrical transport behavior of In_（4-x）Se_（2.95）Ag_x compounds is not significantly optimized by Ag-dopant. Consequently,a maximum ZT of 0.92 at 723 K is obtained by In_（3.98）Se_（2.95）Ag_（0.02） compound that represents 15% enhancement over that of the un-doped one which benefits from the slightly enhanced power factor and the reduced total thermal conductivity.展开更多
The electronic state density and energy bands of Ag-doped anatase TiO2 are studied by WIEN2k software package based on DFT. The calculation results show that the band-gap of anatase titania became bigger after doping ...The electronic state density and energy bands of Ag-doped anatase TiO2 are studied by WIEN2k software package based on DFT. The calculation results show that the band-gap of anatase titania became bigger after doping with Ag metal ions. The band-gap transfers from 2.04 to 2.5 eV, but a new energy band appears among the forbidden band after the Ag atom substitution. The interband width of Ag-TiO2 is 0.17 eV, which is located at –0.07 eV; more excitation and jump routes are opened for the electrons. The lowest excitation energy can achieve 1.2 eV, which may allow the photons with lower energy （at longer wavelength, such as visible light） to be absorbed. Ag ions are implanted into the titania nanotube sample by MEVVA （Metal Vapor Vacuum Arc） implanter. The photo-electrochemical response and photo-degradation experiment of titania nanotube samples implanted with Ag ions are tested under UV and visible light; the results indicated that the performance of implanted titania naotubes is enhanced both under UV and visible light; it is worth mentioning that the photocurrent density can reach 0.145 mA/cm2 under visible light, which is 181 times higher than those of pure TiNT, and the k value of degradation methyl orange can obtain 0.30 h-1, which is 71 times higher than that of pure TiNT. All the experimental results are consistent well with the theoretic ones.展开更多
Using the spray pyrolysis process,the work shows the production of pristine and 6%Ag-doped methylammonium lead iodide bromide(MAPbI2Br)film.Through X-ray diffraction analysis,it was found that Ag doping led to a signi...Using the spray pyrolysis process,the work shows the production of pristine and 6%Ag-doped methylammonium lead iodide bromide(MAPbI2Br)film.Through X-ray diffraction analysis,it was found that Ag doping led to a significant increase in grain size to 29.64 nm,alongside reductions in dislocation line density to 5.39×1014 m−2 and d-spacing to 3.18Å,while maintaining the native cubic crystal structure of MAPbI2Br.This research demonstrates a reduction in deep-level trap states with Ag doping,along with a significant narrowing of the band gap to 1.91 eV in the 6%Ag-doped MAPbI2Br.Moreover,the refractive index and extinction coefficient increased to 2.54 and 2.13,respectively.Regarding solar cell performance,all cells demonstrated encouraging outcomes;still,the 6%Ag-doped cell distinguished itself with a fill factor of 0.82,an open-circuit voltage of 1.07 V,an outstanding short-circuit current density of 11.31 mA/cm²,and an efficiency of 10.03%.These results highlight the effectiveness of Ag doping in improving perovskite solar cell technology,marking a notable progress in this field.展开更多
Alloying is an important strategy in tailoring the functionality of materials.In metal nanoclusters(NCs),the introduction of a heterometal leads to alloy nanoclusters that often outperform the homometal ones in terms ...Alloying is an important strategy in tailoring the functionality of materials.In metal nanoclusters(NCs),the introduction of a heterometal leads to alloy nanoclusters that often outperform the homometal ones in terms of the physical and chemical properties.In this work,a series of four M_(144)(PET)60 alloy NCs(where,M=Au/Ag,PET=–SCH_(2)CH_(2)Ph)are synthesized and characterized.The silver doping into the homogold template(Au_(144))leads to more prominent optical absorption features in the steady-state spectrum in the visible range.Femtosecond transient absorption spectroscopy reveals the effect of Ag doping on the electronic relaxation dynamics compared to Au_(144)and the pump fluence independent dynamics.Electrochemical results reflect a narrowing of HOMO–LUMO gap(E_(g))induced by Ag doping.A temperature dependence of the single-electron charging is also observed for the series of alloy NCs,in which the E_(g)values of the alloy NCs enlarge as the temperature decreases,which is characteristic of semiconducting behavior.展开更多
Chalcopyrite Cu(In,Ga)Se_(2)(CIGS) thin films deposited in a low-temperature process(450℃) usually produce fine grains and poor crystallinity. Herein, different Ag treatment processes, which can decrease the melting ...Chalcopyrite Cu(In,Ga)Se_(2)(CIGS) thin films deposited in a low-temperature process(450℃) usually produce fine grains and poor crystallinity. Herein, different Ag treatment processes, which can decrease the melting temperature and enlarge band gap of the CIGS films, were employed to enhance the quality of thin films in a low-temperature deposition process. It is demonstrated that both the Ag precursor and Ag surface treatment process can heighten the crystallinity of CIGS films and the device efficiency. The former is more obvious than the latter. Furthermore, the Urbach energy is also reduced with Ag doping. This work aims to provide a feasible Ag-doping process for the high-quality CIGS films in a low-temperature process.展开更多
The quaternary diamond-like compounds,A_(2)Cu_(3)In_(3)Te_(8)(A=Cd,Zn,Mn,Mg),are a new class of thermoelectric materials recently proposed by complex structure design.Among them,the Zn_(2)Cu_(3)In_(3)Te_(8) compound p...The quaternary diamond-like compounds,A_(2)Cu_(3)In_(3)Te_(8)(A=Cd,Zn,Mn,Mg),are a new class of thermoelectric materials recently proposed by complex structure design.Among them,the Zn_(2)Cu_(3)In_(3)Te_(8) compound possesses reasonable electrical transport properties but relatively high lattice thermal conductivity.Herein,the effects of Ag substitution on the phase stability and thermoelectric properties of Zn_(2)Cu_(3)In_(3)Te_(8) compound are reported.It is revealed that only the In sites show an appreciable tolerance for Ag doping.Ag substitution at the In sites introduces extra holes and thus results in improved electrical transport properties.Furthermore,the introducing of Ag lowers the sound velocities and enhances the phonon scattering of the Zn_(2)Cu_(3)In_(3)Te_(8) compound,which leads to a substantially reduction in lattice thermal conductivity.Finally,in virtue of the optimization in both electrical and thermal transport properties,the maximal zT value of Zn_(2)Cu_(3)In_(2.8)Ag_(0.2)Te_(8) sample reaches 0.62 at 823 K,which is 43%higher than the pristine sample.展开更多
Rechargeable Li-O2 batteries (LOBs) have been receiving intensive attention because of their ultra-high theoretical energy densityclose to the gasoline. Herein, Ag modified urchin-like α-MnO2 (Ag-MnO2) material with ...Rechargeable Li-O2 batteries (LOBs) have been receiving intensive attention because of their ultra-high theoretical energy densityclose to the gasoline. Herein, Ag modified urchin-like α-MnO2 (Ag-MnO2) material with hierarchical porous structure is obtained bya facile one-step hydrothermal method. Ag-MnO2 possesses thick nanowires and presents hierarchical porous structure of mesoporesand macropores. The unique structure can expose more active sites, and provide continuous pathways for O2 and discharge productsas well. The doping of Ag leads to the change of electronic distribution in α-MnO2 (i.e., more oxygen vacancies), which playimportant roles in improving their intrinsic catalytic activity and conductivity. As a result, LOBs with Ag-MnO2 catalysts exhibit loweroverpotential, higher discharge specific capacity and much better cycle stability compared to pure a-MnO2. LOBs with Ag-MnO2catalysts exhibit a superior discharge specific capacity of 13,131 mA·h·g^-1 at a current density of 200 mA·h·g^-1, a good cycle stabilityof 500 cycles at the capacity of 500 mA·h·g^-1. When current density is increased to 400 mA·h·g^-1, LOBs still retain a long lifespan of170 cycles at a limited capacity of 1,000 mA·h·g^-1.展开更多
The superconducting properties of polycrystalline Sr0.6K0.4Fe2As2 were strongly influenced by Ag doping(Supercond.Sci.Technol.23(2010) 025027).Ag addition is mainly dominated by silver diffusing,so the annealing proce...The superconducting properties of polycrystalline Sr0.6K0.4Fe2As2 were strongly influenced by Ag doping(Supercond.Sci.Technol.23(2010) 025027).Ag addition is mainly dominated by silver diffusing,so the annealing process is one of the essential factors to achieve high quality Ag doped Sr0.6K0.4Fe2As2.In this paper,the optimal annealing conditions were studied for Ag doped Sr0.6K0.4Fe2As2 bulks prepared by a one-step solid reaction method.It is found that the annealing temperature has a strong influence on the superconducting properties,especially on the critical current density Jc.As a result,higher heat treatment temperature(~900℃) is helpful in diffusing Ag and reducing the impurity phase gathered together to improve the grain connectivity.In contrast,low-temperature sintering is counterproductive for Ag doped samples.These results clearly suggest that annealing at ~900℃ is necessary for obtaining high Jc Ag-doped samples.展开更多
Engineering the electronic properties of catalysts to target intermediate adsorption energy as well as harvest high selectivity represents a promising strategy to design advanced electrocatalysts for efficient CO_(2) ...Engineering the electronic properties of catalysts to target intermediate adsorption energy as well as harvest high selectivity represents a promising strategy to design advanced electrocatalysts for efficient CO_(2) electroreduction.Herein,a synergistical tuning on the electronic structure of the Cd Se nanorods is proposed for boosting electrochemical reduction of CO_(2) .The synergy of Ag doping coupled with Se vacancies tuned the electronic structure of the CdSe nanorods,which shows the metalloid characterization and thereby the accelerated electron transfer of CO_(2) electroreduction.Operando synchrotron radiation Fourier transform infrared spectroscopy and theoretical simulation revealed that the Ag doping and Se vacancies accelerated the CO_(2) activation process and lowered the energy barrier for the conversion from CO_(2) to;COOH;as a result,the performance of CO_(2) electroreduction was enhanced.The as-obtained metalloid Ag-doped CdSe nanorods exhibited a 2.7-fold increment in current density and 1.9-fold Faradaic efficiency of CO compared with the pristine CdSe nanorod.展开更多
基金National Natural Science Foundation of China (62104061, 62074052, 61974173 and 52072327)。
文摘Solution-processed Cu(In,Ga)Se_(2)(CIGS) solar cells suffer from serious carrier recombination and power conversion efficiency(PCE) loss because of the poor film properties and easy formation of defects.Herein, we propose Ag&Se co-selenization strategy to enhance the crystallization and passivate harmful defects of the CIGS films. The formation of Ag-Se phase during the selenization process enables the formation of large grains and suppresses the deep level defects. It is found that Ag doping can enlarge the depletion region width, lower the Urbach energy and prolong the carrier lifetime. As a result, a champion solution-processed CIGS solar cell presents a high efficiency of 16.48% with the highly improved opencircuit voltage(VOC) of 662 m V and fill factor(FF) of 75.8%. This work provides an efficient strategy to prepare high quality solution-processed CIGS films for high-performance CIGS solar cells.
基金financially supported by the National Natural Science Foundation of China(Nos.52271025,51927801,and U22A20174)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZC20240173)+1 种基金the Science and Technology Planning Project of Liaoning Province(2023JH2/101700295)the Innovation Foundation of Science and the Technology of Dalian(No.2023JJ12GX021).
文摘Different from full-Heusler compounds,four vacancies in the face-centered cubic crystal structure provide extra sites for enhancing the thermoelectric properties of half-Heusler compounds(HHs).Herein,excess Ag is introduced to the Ni-site vacancies of ZrNiSn to optimize thermoelectric properties.The ZrNiAg_(x)Sn(x=0,0.01,0.02,and 0.03)samples were synthesized by levitation melting and spark plasma sintering.Remarkably,the introduction of excess Ag significantly improves the Seebeck coefficient of ZrNiAg_(0.01)Sn,and a peak power factor of~4.52 mW/(m K^(2))is achieved in ZrNiAg_(0.01)Sn at 923 K,which is enhanced by 22.8%than that of pristine ZrNiSn.As a result,the figure of merit zT of pristine ZrNiSn is enhanced from~0.60 to~0.72 of ZrNiAg_(0.01)Sn at 923 K.Additionally,grain refinement effectively increases the Vickers hardness of ZrNiAg_(0.01)Sn,which is enhanced by 32.8%than that of pristine ZrNiSn.These results demonstrate a viable doping strategy for designing ZrNiSn-based HHs with excellent thermoelectric and mechanical properties.
基金supported by the National Natural Science Foundation of China(Nos.52073290 and 51927803)the Science Fund for Distinguished Young Scholars of Liaoning Province(No.2023JH6/100500004)the Shenyang Science and Technology Plan Project(No.23-407-3-23).
文摘Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg vacancies easily leads to deterioration of electrical properties,especially for p-type Mg_(3)Bi_(2) flm.And the optimization of thermal conductivity of the Mg_(3)Bi_(2)-based flms is barely investigated.In this work,we demonstrate the improved thermoelectric performances of p-type Mg_(3)Bi_(2) through Ag doping by magnetron sputtering.This doping successfully reduces the hole concentration and broadens the band gap of Mg_(3)Bi_(2),thus resulting in a peak power factor of 442μW m−1 K−2 at 525 K.At the same time,Ag doping-induced fuctuations in mass and microscopic strain efectively enhanced the phonon scattering to reduce the lattice thermal conductivity.Consequently,a maximum thermoelectric fgure of merit of 0.22 is achieved at 525 K.Its near-roomtemperature thermoelectric performances demonstrate superior performance compared to many Mg_(3)Bi_(2)-based flms.To further evaluate its potential for thermoelectric power generation,we fabricated a thermoelectric device using Ag-doped Mg_(3)Bi_(2) flms,which achieved a power density of 864μW cm⁻2 at 35 K temperature diference.This study presents an efective strategy for the advancement of Mg_(3)Bi_(2)-based flms for application in micro-thermoelectric devices.
基金supported by King Saud University,Riyadh,Saudi Arabia,under project number RSP2024R397CONAHCYT for the scholarship awarded.
文摘Using the spray pyrolysis process,the work shows the production of pristine and 6%Ag-doped methylammonium lead iodide bromide(MAPbI2Br)film.Through X-ray diffraction analysis,it was found that Ag doping led to a significant increase in grain size to 29.64 nm,alongside reductions in dislocation line density to 5.39×1014 m−2 and d-spacing to 3.18Å,while maintaining the native cubic crystal structure of MAPbI2Br.This research demonstrates a reduction in deep-level trap states with Ag doping,along with a significant narrowing of the band gap to 1.91 eV in the 6%Ag-doped MAPbI2Br.Moreover,the refractive index and extinction coefficient increased to 2.54 and 2.13,respectively.Regarding solar cell performance,all cells demonstrated encouraging outcomes;still,the 6%Ag-doped cell distinguished itself with a fill factor of 0.82,an open-circuit voltage of 1.07 V,an outstanding short-circuit current density of 11.31 mA/cm²,and an efficiency of 10.03%.These results highlight the effectiveness of Ag doping in improving perovskite solar cell technology,marking a notable progress in this field.
基金the National Natural Science Foundation of China(92163117,52072389)the Central Guidance on Science and Technology Development Fund of Zhejiang Province(2024ZY01011)for financial support。
文摘Self-trapped excitons are prevalent in metal halide perovskites(MHPs)characterized by soft lattices and strong exciton-phonon coupling,emitting photons with broadband emission and large Stokes shifts,rendering them particularly well-suited for applications in light-emitting diodes.But their photoluminescence quantum yields(PLQY)are limited by both high exciton binding energy and halogen-vacancy-associated non-radiative recombination.Here,we show that PLQY could be enhanced by a factor of 5.6 from 16%to 89%through doping trace Ag into Cs_(2)NaBiCl_(6)double perovskites,superior to those of previous Cs_(2)NaBiCl_(6)-based emitters.Experimental and theoretical studies reveal that trace Ag-initiated covalent interactions could reduce the exciton binding energy by 0.12 eV due to local symmetry breaking,thus improving the photoexcitation process.Also,this covalent interaction could passivate Cl vacancy defects,suppressing non-radiative recombination.Therefore,Cs2NaBiCl6:0.7%Ag^(+)could accumulate active self-trapped excitons to obtain high PLQY.Assembly of near-infrared light-emitting diodes using Cs_(2)NaBiCl_(6):0.7%Ag^(+)illustrates their valuable applications in nondestructive spectral analysis and night vision illumination.This work shows an effective strategy of improving photoemission of MHPs with high PLQY for advanced optoelectronic applications.
基金supported by the National Natural Science Foundation of China(Nos.52272085 and 52372063)Zhejiang Provincial Natural Science Foundation of China(No.LY23E020002)+1 种基金Ningbo Youth Science and Technology Innovation Leading Talents Project(No.2023QL031)the Postdoctoral Fellowship Program of CPSF(No.GZC20233006).
文摘The zinc indium sulfide(ZnIn_(2)S_(4))semiconductors have garnered significant interest in photocatalysis due to their environmentally friendly characteristics,appropriate bandgap,and high absorption coefficient.However,the exploration of advanced strategies to realize the effective and tailored doping still poses significant challenges in enhancing hydrogen evolution performance.In this work,a mild cation exchange strategy is reported to incorporate Ag cations into flower-like ZnIn_(2)S_(4) microspheres,enabling the selective replacement of Zn atoms by Ag.Remarkably,the as-fabricated Ag-ZnIn_(2)S_(4) exhibited exceptional photocatalytic hydrogen production performance,achieving a rate of 8098μmol·g^(−1)·h^(−1) under visible light irradiation.This is 4 times than that of pristine ZnIn_(2)S_(4)(2002μmol·g^(−1)·h^(−1)),and stands as the highest one among metal-doped-ZnIn_(2)S_(4) photocatalysts ever reported.Along with the theoretical calculations,it has been confirmed that the enhanced photocatalytic hydrogen generation behavior can primarily be attributed to the synergistic effect with improved light absorption,reduced adsorption energy,increased active sites and optimized charge carrier transfer,induced by the cation exchange with Ag in ZnIn_(2)S_(4).This work might provide some valuable insights on the design and development of highly efficient visible light driven photocatalysts for water splitting applications.
基金Supported by the National Natural Science Foundation of China under Grant No 51172012the Fundamental Research Funds for the Central Universities
文摘Antiperovskite compounds Mn3Ag1-xCoxN （x =0.2, 0.5 and 0.8） are synthesized and the doping effect of the magnetic element Co at the Ag site is investigated. The crystal structure is not changed by the introduction of Co. However, with the increase of the content of Co, the spin reorientation gradually disappears and the antiferromagnetic transition changes to the ferromagnetic transition at the elevated temperature when x = 0.8. In addition, all of the magnetic phase transitions at the elevated temperature are always accompanied by the abnormal thermal expansion behaviors and an entropy change. Moreover, when x = 0.8, the coefficient of linear expansion is -1.89 × 10^-6 K^-1 （290-310K, △T =20 K）, which is generally considered as the low thermal expansion.
基金financially supported by the National Natural Science Foundation of China(NSFC)(No.19934003)the Key Program of Natural Science Foundation of Anhui Province(No.KJ2011A259)+1 种基金the Program of Professors and Doctors'Research Startup Foundation of Suzhou College(Nos.2011jb01 and 2011jb02)the Cultivating Base of Anhui Key Laboratory of Spintronics and Nano-materials Research Program(No.2010YKF04)
文摘Polycrystalline samples of Lal-x（Srl-yAgy）x MnO3 （y = 0.0, 0.2, 0.4, 0.6, 1.0） were prepared by the solid-state reaction method. The temperature stability of magnetoresistance and magnetoresistance enhancement in Lal_x（Srl_yAgy）~MnO3 system with both univalent and bivalent elements doped at A site and with unchanged value of Mn~＋/Mn4＋ ratio were explored through the measurements of X-ray diffraction patterns, magnetiza- tion-temperature （M-T） curves, resistivity-temperature （p-T） curves and magnetoresistance-temperature （MR-T） curves. The results are as follows： there are two peaks in the p-T curves of the samples with Ag doping, one is caused by resistance change during the paramagnetism- ferromagnetism transition, and the other is from boundary- dependent scattering of conduction electrons on the boundaries of grains. The peak value of MR increases with increasing Ag doping content, and it increases from 8.2 % for y ---- 0.2 to 29.6 % for y ---- 1.0 under the magnetic field of B = 0.8 T; MR remains a constant of 12 % in the temperature range of 218-168 K for the sample with y = 1.0, and the temperature stability of MR is in favor of the practical application of MR.
基金supported by the analysis support of the State Key Laboratory of New Ceramics and Fine Processing。
文摘The AgCuInGa alloy precursors with different Ag concentrations are fabricated by sputtering an Ag target and a CuInGa target.The precursors are selenized in the H_(2)Se-containing atmosphere to prepare(Ag,Cu)(In,Ga)Se_(2)(ACIGS)absorbers.The beneficial effects of Ag doping are demonstrated and their mechanism is explained.It is found that Ag doping significantly improves the films crystallinity.This is believed to be due to the lower melting point of chalcopyrite phase obtained by the Ag doping.This leads to a higher migration ability of the atoms that in turn promotes grain boundary migration and improves the film crystallinity.The Ga enrichment at the interface between the absorber and the back electrode is also alleviated during the selenization annealing.It is found that Ag doping within a specific range can passivate the band tail and improve the quality of the films.Therefore,carrier recombination is reduced and carrier transport is improved.The negative effects of excessive Ag are also demonstrated and their origin is revealed.Because the atomic size of Ag is different from that of Cu,for the Ag/(Ag+Cu)ratio(AAC)≥0.030,lattice distortion is aggravated,and significant micro-strain appears.The atomic radius of Ag is close to those of In and Ga,so that the continued increase in AAC will give rise to the Ag;or Ag;defects.Both the structural and compositional defects degrade the quality of the absorbers and the device performance.An excellent absorber can be obtained at AAC of 0.015.
基金financially supported by the National Natural Science Foundation of China (No. 51871240)。
文摘Alloying with Se is proved to be feasible to suppress the lattice thermal conductivity(κL)of tellurium by introducing multidimensional lattice defects.However,extra ionization impurity centers induced by Se alloying are harmful to the electric transport properties of the matrix.In this paper,we propose that the incorporation of Ag could successfully compensate the lost carrier mobility(μH)due to Se alloying through the regulation of microstructure,resulting in the higher power factor(PF)than that of samples without Ag.After composition optimization,theκLdecreased from 1.29 W m^(-1)K^(-1) of Te_(0.99)Sb_(0.01) to 1.05 W m^(-1)K^(-1) of Te_(0.94)Ag_(0.02)Se_(0.03)Sb_(0.01) at 350 K,while the PF remained unchanged or even slightly increased.Benefit from the synergistic effect of carrier mobility compensation and phonon scattering,a maximum z T of 0.91 at 573 K and an average z T of 0.57(between 298 and 573 K)are achieved in Te_(0.94)Ag_(0.02)Se_(0.03)Sb_(0.01).This work presents a new strategy for decoupling the thermal and electric parameters of Te-based thermoelectric materials.
基金Projected supported by the National Natural Science Foundation of China (Grant No. 60807001)the Foundation of Henan Educational Committee,China (Grant No. 2010A140017)+1 种基金the Henan Provincial College Young Teachers Program,Chinathe Graduate Innovation of Zhengzhou University,China (Grant No. 11L10102)
文摘A two-step method is adopted to synthesize Ag-doped ZnO nanorods. A ZnO seed layer is first prepared on a glass substrate by thermal decomposition of zinc acetate. Ag-doped ZnO nanorods are then assembled on the ZnO seed layer using the hydrothermal method. The influences of the molar percentage of Ag ions to Zn ions （RAg/zn） on the structural and optical properties of the ZnO nanorods obtained are carefully studied using X-ray diffractometry, scanning electron microscopy and spectrophotometry. Results indicate that Ag ions enter into the crystal lattice through the substitution of Zn ions. The （002） c-axis-preferred orientation of the ZnO nanorods decreases as RAg/Zn increases. At RAg/Zn 〉 1.0%, ZnO nanorods lose their c-axis-preferred orientation and generate Ag precipitates from the ZnO crystal lattice. The average transmissivity in the visible region first increases and then decreases as RAg/Zn increases. The absorption edge is first blue shifted and then red shifted. The influence of Ag doping on the average head face, and axial dimensions of the ZnO nanorods may be optimized to improve the average transmissivity at RAg/Zn 〈 1.0%.
基金supported by the National Natural Science Foundation of China(91422303,21225104,21571020,21233009,and 21301175)
文摘In_4Se_3-based materials are noticeable n-type thermoelectric materials because of lead-free and intrinsically low lattice thermal conductivity,but the In4Se_3-δ crystals（with Se-deficiency,δ） suffer strong anisotropy and cleavage habit. Thus the researches on polycrystalline In_4Se_3-based materials are of great importance. Herein,we experimentally and theoretically investigated the thermoelectric properties of In_（4-x）Se_（2.95）Ag_x polycrystalline compounds. Ag occupying the intercalation or In4 site is energetically most favorable in light of the density functional theory calculation. The maximum solubility of Ag（x_m） is very low（xm 〈 0.03） and the experimental result indicates that the electrical transport behavior of In_（4-x）Se_（2.95）Ag_x compounds is not significantly optimized by Ag-dopant. Consequently,a maximum ZT of 0.92 at 723 K is obtained by In_（3.98）Se_（2.95）Ag_（0.02） compound that represents 15% enhancement over that of the un-doped one which benefits from the slightly enhanced power factor and the reduced total thermal conductivity.
基金Supported by National Natural Science Foundation of China (No. 10975020)Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University
文摘The electronic state density and energy bands of Ag-doped anatase TiO2 are studied by WIEN2k software package based on DFT. The calculation results show that the band-gap of anatase titania became bigger after doping with Ag metal ions. The band-gap transfers from 2.04 to 2.5 eV, but a new energy band appears among the forbidden band after the Ag atom substitution. The interband width of Ag-TiO2 is 0.17 eV, which is located at –0.07 eV; more excitation and jump routes are opened for the electrons. The lowest excitation energy can achieve 1.2 eV, which may allow the photons with lower energy （at longer wavelength, such as visible light） to be absorbed. Ag ions are implanted into the titania nanotube sample by MEVVA （Metal Vapor Vacuum Arc） implanter. The photo-electrochemical response and photo-degradation experiment of titania nanotube samples implanted with Ag ions are tested under UV and visible light; the results indicated that the performance of implanted titania naotubes is enhanced both under UV and visible light; it is worth mentioning that the photocurrent density can reach 0.145 mA/cm2 under visible light, which is 181 times higher than those of pure TiNT, and the k value of degradation methyl orange can obtain 0.30 h-1, which is 71 times higher than that of pure TiNT. All the experimental results are consistent well with the theoretic ones.
文摘Using the spray pyrolysis process,the work shows the production of pristine and 6%Ag-doped methylammonium lead iodide bromide(MAPbI2Br)film.Through X-ray diffraction analysis,it was found that Ag doping led to a significant increase in grain size to 29.64 nm,alongside reductions in dislocation line density to 5.39×1014 m−2 and d-spacing to 3.18Å,while maintaining the native cubic crystal structure of MAPbI2Br.This research demonstrates a reduction in deep-level trap states with Ag doping,along with a significant narrowing of the band gap to 1.91 eV in the 6%Ag-doped MAPbI2Br.Moreover,the refractive index and extinction coefficient increased to 2.54 and 2.13,respectively.Regarding solar cell performance,all cells demonstrated encouraging outcomes;still,the 6%Ag-doped cell distinguished itself with a fill factor of 0.82,an open-circuit voltage of 1.07 V,an outstanding short-circuit current density of 11.31 mA/cm²,and an efficiency of 10.03%.These results highlight the effectiveness of Ag doping in improving perovskite solar cell technology,marking a notable progress in this field.
基金R.J.thanks the financial support from the National Science Foundation(No.DMR-1808675)G.W.acknowledges the funding support from National Science Foundation PAPID CHE(No.2034498)H.W.thanks the financial support from,the Air Force Office of Scientific Research(AFOSR)Nos.(FA9550-17-1-0099 and sFA9550-21-1-0192).
文摘Alloying is an important strategy in tailoring the functionality of materials.In metal nanoclusters(NCs),the introduction of a heterometal leads to alloy nanoclusters that often outperform the homometal ones in terms of the physical and chemical properties.In this work,a series of four M_(144)(PET)60 alloy NCs(where,M=Au/Ag,PET=–SCH_(2)CH_(2)Ph)are synthesized and characterized.The silver doping into the homogold template(Au_(144))leads to more prominent optical absorption features in the steady-state spectrum in the visible range.Femtosecond transient absorption spectroscopy reveals the effect of Ag doping on the electronic relaxation dynamics compared to Au_(144)and the pump fluence independent dynamics.Electrochemical results reflect a narrowing of HOMO–LUMO gap(E_(g))induced by Ag doping.A temperature dependence of the single-electron charging is also observed for the series of alloy NCs,in which the E_(g)values of the alloy NCs enlarge as the temperature decreases,which is characteristic of semiconducting behavior.
基金The work was supported by the National Key R&D Program of China(No.2018YFB1500200)National Natural Science Foundation of China(Nos.61774089 and 61974076)Natural Science Foundation of Tianjin(No.18JCZDJC31200)。
文摘Chalcopyrite Cu(In,Ga)Se_(2)(CIGS) thin films deposited in a low-temperature process(450℃) usually produce fine grains and poor crystallinity. Herein, different Ag treatment processes, which can decrease the melting temperature and enlarge band gap of the CIGS films, were employed to enhance the quality of thin films in a low-temperature deposition process. It is demonstrated that both the Ag precursor and Ag surface treatment process can heighten the crystallinity of CIGS films and the device efficiency. The former is more obvious than the latter. Furthermore, the Urbach energy is also reduced with Ag doping. This work aims to provide a feasible Ag-doping process for the high-quality CIGS films in a low-temperature process.
基金This work was supported by the National Key Research and Development Program of China(grant nos.2018YFB0703600 and 2018YFA0702100)the National Natural Science Foundation of China(grant nos.51472241,51772186,51632005,and 51371194)the Science and Technology Commission of Shanghai Municipality(grant no.16DZ2260601).
文摘The quaternary diamond-like compounds,A_(2)Cu_(3)In_(3)Te_(8)(A=Cd,Zn,Mn,Mg),are a new class of thermoelectric materials recently proposed by complex structure design.Among them,the Zn_(2)Cu_(3)In_(3)Te_(8) compound possesses reasonable electrical transport properties but relatively high lattice thermal conductivity.Herein,the effects of Ag substitution on the phase stability and thermoelectric properties of Zn_(2)Cu_(3)In_(3)Te_(8) compound are reported.It is revealed that only the In sites show an appreciable tolerance for Ag doping.Ag substitution at the In sites introduces extra holes and thus results in improved electrical transport properties.Furthermore,the introducing of Ag lowers the sound velocities and enhances the phonon scattering of the Zn_(2)Cu_(3)In_(3)Te_(8) compound,which leads to a substantially reduction in lattice thermal conductivity.Finally,in virtue of the optimization in both electrical and thermal transport properties,the maximal zT value of Zn_(2)Cu_(3)In_(2.8)Ag_(0.2)Te_(8) sample reaches 0.62 at 823 K,which is 43%higher than the pristine sample.
基金This work was financially supported by High-level Talents'Discipline Construction Fund of Shandong University(No.31370089963078)Shandong Provincial Science and Technology Major Project(Nos.2016GGX104001,2017CXGC1010,and 2018JMRH0211)+2 种基金the Fundamental Research Funds of Shandong University(Nos.2016JC005,2017JC042 and 2017JC010)the Natural Science Foundation of Shandong Province(No.ZR2017MEM002)School Research Startup Expenses of Harbin Institute of Technology(Shenzhen)(No.DD29100027).
文摘Rechargeable Li-O2 batteries (LOBs) have been receiving intensive attention because of their ultra-high theoretical energy densityclose to the gasoline. Herein, Ag modified urchin-like α-MnO2 (Ag-MnO2) material with hierarchical porous structure is obtained bya facile one-step hydrothermal method. Ag-MnO2 possesses thick nanowires and presents hierarchical porous structure of mesoporesand macropores. The unique structure can expose more active sites, and provide continuous pathways for O2 and discharge productsas well. The doping of Ag leads to the change of electronic distribution in α-MnO2 (i.e., more oxygen vacancies), which playimportant roles in improving their intrinsic catalytic activity and conductivity. As a result, LOBs with Ag-MnO2 catalysts exhibit loweroverpotential, higher discharge specific capacity and much better cycle stability compared to pure a-MnO2. LOBs with Ag-MnO2catalysts exhibit a superior discharge specific capacity of 13,131 mA·h·g^-1 at a current density of 200 mA·h·g^-1, a good cycle stabilityof 500 cycles at the capacity of 500 mA·h·g^-1. When current density is increased to 400 mA·h·g^-1, LOBs still retain a long lifespan of170 cycles at a limited capacity of 1,000 mA·h·g^-1.
基金supported by the Beijing Municipal Science and Technology Commission (Grant No. Z09010300820907)the National Natural Science Foundation of China (Grant No. 50802093)the National Basic Research Program of China (Grant No. 2006CB601004)
文摘The superconducting properties of polycrystalline Sr0.6K0.4Fe2As2 were strongly influenced by Ag doping(Supercond.Sci.Technol.23(2010) 025027).Ag addition is mainly dominated by silver diffusing,so the annealing process is one of the essential factors to achieve high quality Ag doped Sr0.6K0.4Fe2As2.In this paper,the optimal annealing conditions were studied for Ag doped Sr0.6K0.4Fe2As2 bulks prepared by a one-step solid reaction method.It is found that the annealing temperature has a strong influence on the superconducting properties,especially on the critical current density Jc.As a result,higher heat treatment temperature(~900℃) is helpful in diffusing Ag and reducing the impurity phase gathered together to improve the grain connectivity.In contrast,low-temperature sintering is counterproductive for Ag doped samples.These results clearly suggest that annealing at ~900℃ is necessary for obtaining high Jc Ag-doped samples.
基金supported by the National Natural Science Foundation of China(12025505 and 21873050)China Ministry of Science and Technology(2017YFA0208300)+1 种基金the Open Fund Project of State Key Laboratory of Environmentally Friendly Energy Materials(20KFHG08)the Youth Innovation Promotion Association CAS(CX2310007007 and CX2310000091)。
文摘Engineering the electronic properties of catalysts to target intermediate adsorption energy as well as harvest high selectivity represents a promising strategy to design advanced electrocatalysts for efficient CO_(2) electroreduction.Herein,a synergistical tuning on the electronic structure of the Cd Se nanorods is proposed for boosting electrochemical reduction of CO_(2) .The synergy of Ag doping coupled with Se vacancies tuned the electronic structure of the CdSe nanorods,which shows the metalloid characterization and thereby the accelerated electron transfer of CO_(2) electroreduction.Operando synchrotron radiation Fourier transform infrared spectroscopy and theoretical simulation revealed that the Ag doping and Se vacancies accelerated the CO_(2) activation process and lowered the energy barrier for the conversion from CO_(2) to;COOH;as a result,the performance of CO_(2) electroreduction was enhanced.The as-obtained metalloid Ag-doped CdSe nanorods exhibited a 2.7-fold increment in current density and 1.9-fold Faradaic efficiency of CO compared with the pristine CdSe nanorod.
