The precise measurement of Al, Mg, Ca, and Zn composition in copper slag is crucial for effective process control of copper pyrometallurgy. In this study, a remote laser-induced breakdown spectroscopy(LIBS) system was...The precise measurement of Al, Mg, Ca, and Zn composition in copper slag is crucial for effective process control of copper pyrometallurgy. In this study, a remote laser-induced breakdown spectroscopy(LIBS) system was utilized for the spectral analysis of copper slag samples at a distance of 2.5 m. The composition of copper slag was then analyzed using both the calibration curve(CC) method and the partial least squares regression(PLSR) analysis method based on the characteristic spectral intensity ratio. The performance of the two analysis methods was gauged through the determination coefficient(R^(2)), average relative error(ARE), root mean square error of calibration(RMSEC), and root mean square error of prediction(RMSEP). The results demonstrate that the PLSR method significantly improved both R^(2) for the calibration and test sets while reducing ARE, RMSEC, and RMSEP by 50% compared to the CC method. The results suggest that the combination of LIBS and PLSR is a viable approach for effectively detecting the elemental concentration in copper slag and holds potential for online detection of the elemental composition of high-temperature molten copper slag.展开更多
Although the internal electric field(IEF)of photocatalysts is acknowledged as a potent driving force for photocharge separation,modulating the IEF intensity to achieve enhanced photocatalytic performances remains a ch...Although the internal electric field(IEF)of photocatalysts is acknowledged as a potent driving force for photocharge separation,modulating the IEF intensity to achieve enhanced photocatalytic performances remains a challenge.Herein,cuprous sulfide nanosheets with different Cu vacancy concentration were employed to study IEF modulation and corresponding direct charge transfer.Among the samples,Cu_(1.8)S nanosheets possessed intensified IEF intensity compared with those of Cu_(2)S and Cu_(1.95)S nanosheets,suggesting that an enhanced IEF intensity could be achieved by introducing more Cu vacancies.This intensified IEF of Cu_(1.8)S nanosheets induced numerous photogenerated electrons to migrate to its surface,and the dissociative electrons were then captured by Cu vacancies,resulting in efficient charge separation spatially.In addition,the Cu vacancies on Cu_(1.8)S nanosheets accumulated electrons as active sites to lower the energy barrier of rate-determining step of CO_(2)photoreduction,leading to the selective conversion of CO_(2)to CO.Herein,the manipulation of IEF intensity through Cu vacancy concentration regulation of cuprous sulfide photocatalysts for efficient charge separation has been discussed,providing a scientific strategy to rationally improve photocata lytic performances for solar energy conversion.展开更多
Conductor materials with good mechanical performance as well as high electrical and thermal conductivities are particularly important to break through the current bottle-neck limit(~ 100 T) of pulsed magnets. Here, we...Conductor materials with good mechanical performance as well as high electrical and thermal conductivities are particularly important to break through the current bottle-neck limit(~ 100 T) of pulsed magnets. Here, we perform systematic studies on the elastic properties of the Cu–6wt% Ag alloy wire, which is a promising candidate material for the new-generation pulsed magnets, by employing two independent ultrasonic techniques, i.e., resonant ultrasound spectroscopy(RUS) and ultrasound pulse-echo experiments. Our RUS measurements manifest that the elastic properties of the Cu–6wt% Ag alloy wires can be improved by an electroplastic drawing procedure as compared with the conventional cold drawing. We also take this opportunity to test the availability of our newly-built ultrasound pulse-echo facility at the Wuhan National High Magnetic Field Center(WHMFC, China), and the results suggest that the elastic performance of the electroplastically-drawn Cu–6wt% Ag alloy wire remains excellent without anomalous softening under extreme conditions,e.g., in ultra-high magnetic field up to 50 T and nitrogen or helium cryogenic liquids.展开更多
Electrocatalytic nitrate reduction reaction (NO_(3)-RR) to ammonia under ambient conditions is expected to be a green process for ammonia synthesis and alleviate water pollution issues.We report a CuO nanoparticles in...Electrocatalytic nitrate reduction reaction (NO_(3)-RR) to ammonia under ambient conditions is expected to be a green process for ammonia synthesis and alleviate water pollution issues.We report a CuO nanoparticles incorporated on nitrogen-doped porous carbon (CuO@NC) catalyst for NO_(3)-RR.Part of Cu(Ⅱ) is reduced to Cu(Ⅰ) during the NO_(3)-RR process to construct Cu(Ⅰ)-Cu(Ⅱ) pairs,confirmed by in situ X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy.Density functional theory (DFT) calculations indicated that the formation of Cu(Ⅰ) could provide a reaction path with smaller energy barrier for NO_(3)-RR,while Cu(Ⅱ) effectively suppressed the competition of hydrogen evolution reaction (HER).As a result,CuO@NC catalyst achieved a Faradaic efficiency of 84.2% at -0.49 V versus reversible hydrogen electrode (RHE),and a NH_(3)yield rate of 17.2 mg h^(-1)mg^(-1)cat.at -0.79 V vs.RHE,higher than the HaberBosch process (<3.4 g h^(-1)g^(-1)cat.).This work may open a new avenue for effective NO_(3)-RR by modulating oxidation states.展开更多
Solution-processed chalcopyrite solar cells are widely regarded as a promising alternative method in reducing the cost compared with vacuum-based techniques.It is noted that the absorber layer usually needs to be prep...Solution-processed chalcopyrite solar cells are widely regarded as a promising alternative method in reducing the cost compared with vacuum-based techniques.It is noted that the absorber layer usually needs to be prepared under a high insert pressure(~1.6 atm)to suppress element loss or under a mild pressure but additional surface etching is needed for fabricating high efficient solar cell.Herein,a copper gradient structured precursor is proposed to prepare CuIn(S,Se)_(2)(CISSe)film under a mild pressure(1.1 atm).The designed gradient Cu not only promotes crystal grain growth and tailors the defects,but also avoids the surface etching of the formed CISSe film for the fabrication of high efficient solar cells.Further,Cu gradient design decreases the conduction band offset of heterojunction,boosting the carriers transport across the p-n heterojunction.Accordingly,a 13,35%efficient CISSe solar cell,comparable to the high efficient CISSe solar cell prepared by this method under high pressure or with film surface etching,is fabricated.This work provides a facile pathway to fabricate high efficient solution-processed chalcopyrite solar cell,avoiding high selenization pressure and film etching,and shows huge potential for solutionprocessed copper-based solar cells.展开更多
The development of efficient and durable electrocatalysts for oxygen reduction reaction(ORR)holds a pivotal significance in the successful commercialization of proton exchange membrane fuel cells(PEMFCs)but is still c...The development of efficient and durable electrocatalysts for oxygen reduction reaction(ORR)holds a pivotal significance in the successful commercialization of proton exchange membrane fuel cells(PEMFCs)but is still challenging.Herein,we report a worm-liked PtCu nanocrystals dispersed on nitrogen-doped carbon hollow microspheres(Pt_(0.38)Cu_(0.62)/N-HCS).Benefiting from its structural and compositional advantages,the resulting Pt_(0.38)Cu_(0.62)/N-HCS catalyst delivers exceptional electrocatalytic activity for ORR,with a half-wave potential(E_(1/2))of 0.837 V,a mass activity of 0.672 A mgPt^(-1),and a Tafel slope of 50.66 mV dec^(-1),surpassing that of commercial Pt/C.Moreover,the Pt_(0.38)Cu_(0.62)/N-HCS follows the desired four-electron transfer mechanism throughout the ORR process,thereby displaying a high selectivity for direct reduction of O_(2)to H_(2)O.Remarkably,this catalyst also showcases high stability,with only a 25 mV drop in E_(1/2)after 10,000 cycles in an acidic electrolyte.Theoretical calculations elucidate the incorporation of Cu into Pt lattice induces compressive strain,which effectively tailors the d band center of Pt active sites and strengthens the surface chemisorption of O_(2)molecules on PtCu alloys.Consequently,the Pt_(0.38)Cu_(0.62)/N-HCS catalyst exhibits an improved ability to adsorb O_(2)molecules on its surface,accelerating the reaction kinetics of O_(2)conversion to*OOH.Additionally,Cu atoms,not only serving as sacrificial anode,undergo preferential oxidation during PEMFCs operation when compared to Pt,but also the stable Cu species in PtCu alloys contributes significantly to maintaining the strain effect,collectively enhancing both activity and durability.Overall,this research offers an effective and promising approach to enhance the activity and stability of Pt-based ORR electrocatalysts in PEMFCs.展开更多
基金supported by funding for research activities of postdoctoral researchers in Anhui Provincespecial funds for developing Anhui Province’s industrial “three highs” and high-tech industries。
文摘The precise measurement of Al, Mg, Ca, and Zn composition in copper slag is crucial for effective process control of copper pyrometallurgy. In this study, a remote laser-induced breakdown spectroscopy(LIBS) system was utilized for the spectral analysis of copper slag samples at a distance of 2.5 m. The composition of copper slag was then analyzed using both the calibration curve(CC) method and the partial least squares regression(PLSR) analysis method based on the characteristic spectral intensity ratio. The performance of the two analysis methods was gauged through the determination coefficient(R^(2)), average relative error(ARE), root mean square error of calibration(RMSEC), and root mean square error of prediction(RMSEP). The results demonstrate that the PLSR method significantly improved both R^(2) for the calibration and test sets while reducing ARE, RMSEC, and RMSEP by 50% compared to the CC method. The results suggest that the combination of LIBS and PLSR is a viable approach for effectively detecting the elemental concentration in copper slag and holds potential for online detection of the elemental composition of high-temperature molten copper slag.
基金supported by the National Natural Science Foundation of China(52200123)the Open Project of Key Laboratory of Green Chemical Engineering Process of Ministry of Education(GCP2022007)the Scientific Research and Innovation Team Program of Sichuan University of Science and Engineering(SUSE652A014)。
文摘Although the internal electric field(IEF)of photocatalysts is acknowledged as a potent driving force for photocharge separation,modulating the IEF intensity to achieve enhanced photocatalytic performances remains a challenge.Herein,cuprous sulfide nanosheets with different Cu vacancy concentration were employed to study IEF modulation and corresponding direct charge transfer.Among the samples,Cu_(1.8)S nanosheets possessed intensified IEF intensity compared with those of Cu_(2)S and Cu_(1.95)S nanosheets,suggesting that an enhanced IEF intensity could be achieved by introducing more Cu vacancies.This intensified IEF of Cu_(1.8)S nanosheets induced numerous photogenerated electrons to migrate to its surface,and the dissociative electrons were then captured by Cu vacancies,resulting in efficient charge separation spatially.In addition,the Cu vacancies on Cu_(1.8)S nanosheets accumulated electrons as active sites to lower the energy barrier of rate-determining step of CO_(2)photoreduction,leading to the selective conversion of CO_(2)to CO.Herein,the manipulation of IEF intensity through Cu vacancy concentration regulation of cuprous sulfide photocatalysts for efficient charge separation has been discussed,providing a scientific strategy to rationally improve photocata lytic performances for solar energy conversion.
基金Project supported by the National Key R&D Program of China (Grant Nos. 2022YFA1602602 and 2023YFA1609600)the National Natural Science Foundation of China (Grant No. U23A20580)+3 种基金the open research fund of Songshan Lake Materials Laboratory (Grant No. 2022SLABFN27)Beijing National Laboratory for Condensed Matter Physics (Grant No. 2024BNLCMPKF004)Guangdong Basic and Applied Basic Research Foundation (Grant No. 2022B1515120020)the interdisciplinary program of Wuhan National High Magnetic Field Center at Huazhong University of Science and Technology (Grant No. WHMFC202132)。
文摘Conductor materials with good mechanical performance as well as high electrical and thermal conductivities are particularly important to break through the current bottle-neck limit(~ 100 T) of pulsed magnets. Here, we perform systematic studies on the elastic properties of the Cu–6wt% Ag alloy wire, which is a promising candidate material for the new-generation pulsed magnets, by employing two independent ultrasonic techniques, i.e., resonant ultrasound spectroscopy(RUS) and ultrasound pulse-echo experiments. Our RUS measurements manifest that the elastic properties of the Cu–6wt% Ag alloy wires can be improved by an electroplastic drawing procedure as compared with the conventional cold drawing. We also take this opportunity to test the availability of our newly-built ultrasound pulse-echo facility at the Wuhan National High Magnetic Field Center(WHMFC, China), and the results suggest that the elastic performance of the electroplastically-drawn Cu–6wt% Ag alloy wire remains excellent without anomalous softening under extreme conditions,e.g., in ultra-high magnetic field up to 50 T and nitrogen or helium cryogenic liquids.
基金National Natural Science Foundation of China (52371228, 52402045)fund of Key Laboratory of Advanced Materials of Ministry of Education(Advmat-2414)。
文摘Electrocatalytic nitrate reduction reaction (NO_(3)-RR) to ammonia under ambient conditions is expected to be a green process for ammonia synthesis and alleviate water pollution issues.We report a CuO nanoparticles incorporated on nitrogen-doped porous carbon (CuO@NC) catalyst for NO_(3)-RR.Part of Cu(Ⅱ) is reduced to Cu(Ⅰ) during the NO_(3)-RR process to construct Cu(Ⅰ)-Cu(Ⅱ) pairs,confirmed by in situ X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy.Density functional theory (DFT) calculations indicated that the formation of Cu(Ⅰ) could provide a reaction path with smaller energy barrier for NO_(3)-RR,while Cu(Ⅱ) effectively suppressed the competition of hydrogen evolution reaction (HER).As a result,CuO@NC catalyst achieved a Faradaic efficiency of 84.2% at -0.49 V versus reversible hydrogen electrode (RHE),and a NH_(3)yield rate of 17.2 mg h^(-1)mg^(-1)cat.at -0.79 V vs.RHE,higher than the HaberBosch process (<3.4 g h^(-1)g^(-1)cat.).This work may open a new avenue for effective NO_(3)-RR by modulating oxidation states.
基金supported by the National Natural Science Foundation of China(U1902218).
文摘Solution-processed chalcopyrite solar cells are widely regarded as a promising alternative method in reducing the cost compared with vacuum-based techniques.It is noted that the absorber layer usually needs to be prepared under a high insert pressure(~1.6 atm)to suppress element loss or under a mild pressure but additional surface etching is needed for fabricating high efficient solar cell.Herein,a copper gradient structured precursor is proposed to prepare CuIn(S,Se)_(2)(CISSe)film under a mild pressure(1.1 atm).The designed gradient Cu not only promotes crystal grain growth and tailors the defects,but also avoids the surface etching of the formed CISSe film for the fabrication of high efficient solar cells.Further,Cu gradient design decreases the conduction band offset of heterojunction,boosting the carriers transport across the p-n heterojunction.Accordingly,a 13,35%efficient CISSe solar cell,comparable to the high efficient CISSe solar cell prepared by this method under high pressure or with film surface etching,is fabricated.This work provides a facile pathway to fabricate high efficient solution-processed chalcopyrite solar cell,avoiding high selenization pressure and film etching,and shows huge potential for solutionprocessed copper-based solar cells.
基金the Young Elite Scientists Sponsorship Program by CAST(2021QNRC001)Natural Science Foundation of Chongqing(CSTB2022NSCQ-MSX0557,cstb2023nscq-msx0979)+3 种基金Talent Introduction of Chongqing University of Science and Technology(ckrc2021050,ckrc20230401,ckrc2021053)the Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN202201532,KJQN202301542)the National Natural Science Foundation of China(22109016)Open Research Fund of CNMGE Platform&NSCC-TJ(CNMGE2023016).
文摘The development of efficient and durable electrocatalysts for oxygen reduction reaction(ORR)holds a pivotal significance in the successful commercialization of proton exchange membrane fuel cells(PEMFCs)but is still challenging.Herein,we report a worm-liked PtCu nanocrystals dispersed on nitrogen-doped carbon hollow microspheres(Pt_(0.38)Cu_(0.62)/N-HCS).Benefiting from its structural and compositional advantages,the resulting Pt_(0.38)Cu_(0.62)/N-HCS catalyst delivers exceptional electrocatalytic activity for ORR,with a half-wave potential(E_(1/2))of 0.837 V,a mass activity of 0.672 A mgPt^(-1),and a Tafel slope of 50.66 mV dec^(-1),surpassing that of commercial Pt/C.Moreover,the Pt_(0.38)Cu_(0.62)/N-HCS follows the desired four-electron transfer mechanism throughout the ORR process,thereby displaying a high selectivity for direct reduction of O_(2)to H_(2)O.Remarkably,this catalyst also showcases high stability,with only a 25 mV drop in E_(1/2)after 10,000 cycles in an acidic electrolyte.Theoretical calculations elucidate the incorporation of Cu into Pt lattice induces compressive strain,which effectively tailors the d band center of Pt active sites and strengthens the surface chemisorption of O_(2)molecules on PtCu alloys.Consequently,the Pt_(0.38)Cu_(0.62)/N-HCS catalyst exhibits an improved ability to adsorb O_(2)molecules on its surface,accelerating the reaction kinetics of O_(2)conversion to*OOH.Additionally,Cu atoms,not only serving as sacrificial anode,undergo preferential oxidation during PEMFCs operation when compared to Pt,but also the stable Cu species in PtCu alloys contributes significantly to maintaining the strain effect,collectively enhancing both activity and durability.Overall,this research offers an effective and promising approach to enhance the activity and stability of Pt-based ORR electrocatalysts in PEMFCs.
