In situ growth of co-catalysts on BiVO_(4)(BVO)to enhance photoelectrochemical(PEC)water splitting performance has been extensively reported.However,the understanding of the synergistic effects among various elements,...In situ growth of co-catalysts on BiVO_(4)(BVO)to enhance photoelectrochemical(PEC)water splitting performance has been extensively reported.However,the understanding of the synergistic effects among various elements,especially at the interface between the semiconductor and cocatalyst,has received insufficient attention.In this study,we report a Co,Ni and Mn trimetallic fluoride-modified BVO photoanode featuring a unique interfacial chemical bond(V-F).Under AM 1.5 G illumination,an exciting photocurrent density of 6.05 mA cm^(-2)was achieved at 1.23 V vs.RHE by the integrated BVO/CoNi_(0.18)Mn_(0.12)(OH)_(x)F photoanode and over 98%of the initial photocurrent was maintained after 10 h of photoelectrolysis.Control experiments and theoretical calculations demonstrate that the V-F interfacial bond stabilizes the Co^(2+)active sites.It serves as a transmission gear,interlinking the migration of interfacial charge and the regeneration of cocatalyst,endowing the photoanode with significant activity and stability.Furthermore,we have systematically elucidated the role of the individual Co,Ni,and Mn components in the synergistic cocatalyst layer.The interfacial modification provides novel insights into developing advanced photoanodes towards PEC water splitting.展开更多
Selective electrocatalytic semi-hydrogenation(ECSH)of alkynes in water using Cu catalysts is highly relevant for the production of value-added chemicals.However,achieving high olefin selectivity still poses extreme ch...Selective electrocatalytic semi-hydrogenation(ECSH)of alkynes in water using Cu catalysts is highly relevant for the production of value-added chemicals.However,achieving high olefin selectivity still poses extreme challenges due to the susceptibility of the copper cathode in a reduction environment.Herein,a small molecule modulation electrodeposition strategy is introduced that regulates the structure of Cubased materials through modification with citric acid(CA)ligands,aiming for highly active and selective ECSH.The as-prepared EDCu-CA electrode achieves more than 97%alkyne conversion and 99%olefin selectivity.In-situ Raman and Auger electron spectroscopy(AES)data provide evidence that active Cu^(+)sites can stably exist in the EDCu-CA during the catalytic process.Density functional theory(DFT)calculations indicate that the modulation by CA contributes to maintaining Cu in a positive valence state,and Cu^(+)can inhibit the over-hydrogenation of olefins.Moreover,by utilizing a large-area electrode for longterm electrolysis,g-level conversion and a 92%separation yield of olefin can be achieved,demonstrating a viable application prospect.This study offers a promising route for designing Cu-based catalysts for the highly selective electrocata lytic conversion of organic substrates to value-added chemicals in water.展开更多
In order to repair and reuse remaining quenching surface(RQS)divided into severely worn surface(SWun-S)and mildly worn surface(MWun-S)of abandoned gray cast iron guide rail,inspired by the bionic theory,varying forms ...In order to repair and reuse remaining quenching surface(RQS)divided into severely worn surface(SWun-S)and mildly worn surface(MWun-S)of abandoned gray cast iron guide rail,inspired by the bionic theory,varying forms of bionic units such as spot(Sp-S),striation(St-S),and reticulation(Re-S)were fabricated on RQS of gray cast iron through laser processing technology.Firstly,the microstructure,phase composition,and microhardness of bionic units and RQS were analyzed by optical microscopy as well as X-ray diffraction instrument and scanning electron microscopy,respectively.Secondly,the oil lubrication wear experiment was performed on homemade line reciprocating wear machine.The results demonstrated that the bionic units had a significant effect on improving wear resistance of RQS of abandoned guide rail due to the microstructure and higher hardness.In addition,the weight loss ratios of MWun-S,Sp-S,St-S,and Re-S samples were decreased by 36.72%,36.78%,62.26%,and 80.39%,respectively,compared with that of SWun-S sample.The mechanism of wear resistance enhancement was also discussed.展开更多
Although many emerging new phenomena have been unraveled in two dimensional(2D)materials with long-range spin orderings,the usually low critical temperature in van der Waals(vdW)magnetic material has thus far hindered...Although many emerging new phenomena have been unraveled in two dimensional(2D)materials with long-range spin orderings,the usually low critical temperature in van der Waals(vdW)magnetic material has thus far hindered the related practical applications.Here,we show that ferromagnetism can hold above 300 K in a metallic phase of 1T-CrTe2 down to the ultra-thin limit.It thus makes CrTe2 so far the only known exfoliated ultra-thin vdW magnets with intrinsic long-range magnetic ordering above room temperature.An in-plane room-temperature negative anisotropic magnetoresistance(AMR)was obtained in ultra-thin CrTe2 devices,with a sign change in the AMR at lower temperature,with−0.6%and+5%at 300 and 10 K,respectively.Our findings provide insights into magnetism in ultra-thin CrTe2,expanding the vdW crystals toolbox for future room-temperature spintronic applications.展开更多
An in-band optical signal-to-noise ratio （OSNR） monitoring technique with high resolution and large measurement range is demonstrated based on low- bandwidth coherent receiver and a tunable laser. The measurement ra...An in-band optical signal-to-noise ratio （OSNR） monitoring technique with high resolution and large measurement range is demonstrated based on low- bandwidth coherent receiver and a tunable laser. The measurement range of OSNR is from 10 to 25 dB and the resolution can be controlled about ±1 dB.展开更多
文摘In situ growth of co-catalysts on BiVO_(4)(BVO)to enhance photoelectrochemical(PEC)water splitting performance has been extensively reported.However,the understanding of the synergistic effects among various elements,especially at the interface between the semiconductor and cocatalyst,has received insufficient attention.In this study,we report a Co,Ni and Mn trimetallic fluoride-modified BVO photoanode featuring a unique interfacial chemical bond(V-F).Under AM 1.5 G illumination,an exciting photocurrent density of 6.05 mA cm^(-2)was achieved at 1.23 V vs.RHE by the integrated BVO/CoNi_(0.18)Mn_(0.12)(OH)_(x)F photoanode and over 98%of the initial photocurrent was maintained after 10 h of photoelectrolysis.Control experiments and theoretical calculations demonstrate that the V-F interfacial bond stabilizes the Co^(2+)active sites.It serves as a transmission gear,interlinking the migration of interfacial charge and the regeneration of cocatalyst,endowing the photoanode with significant activity and stability.Furthermore,we have systematically elucidated the role of the individual Co,Ni,and Mn components in the synergistic cocatalyst layer.The interfacial modification provides novel insights into developing advanced photoanodes towards PEC water splitting.
基金financially supported by the National Natural Science Foundation of China(NSFC)(22179056,22172018)the Liaoning Revitalization Talents Program(XLYC2002097,1807210)+2 种基金the Key Projects of Liaoning Provincial Education Department(JYTZD2023001)the Fundamental Research Funds for the Central Universities(DUT23LAB611)Yingkou Talents Program。
文摘Selective electrocatalytic semi-hydrogenation(ECSH)of alkynes in water using Cu catalysts is highly relevant for the production of value-added chemicals.However,achieving high olefin selectivity still poses extreme challenges due to the susceptibility of the copper cathode in a reduction environment.Herein,a small molecule modulation electrodeposition strategy is introduced that regulates the structure of Cubased materials through modification with citric acid(CA)ligands,aiming for highly active and selective ECSH.The as-prepared EDCu-CA electrode achieves more than 97%alkyne conversion and 99%olefin selectivity.In-situ Raman and Auger electron spectroscopy(AES)data provide evidence that active Cu^(+)sites can stably exist in the EDCu-CA during the catalytic process.Density functional theory(DFT)calculations indicate that the modulation by CA contributes to maintaining Cu in a positive valence state,and Cu^(+)can inhibit the over-hydrogenation of olefins.Moreover,by utilizing a large-area electrode for longterm electrolysis,g-level conversion and a 92%separation yield of olefin can be achieved,demonstrating a viable application prospect.This study offers a promising route for designing Cu-based catalysts for the highly selective electrocata lytic conversion of organic substrates to value-added chemicals in water.
基金supported by Project 985-High Performance Materials of Jilin UniversityProject 985-Bionic Engineering Science and Technology Innovationdouble first-class project by Jilin Province and Jilin University(SXGJXX2017-14).
文摘In order to repair and reuse remaining quenching surface(RQS)divided into severely worn surface(SWun-S)and mildly worn surface(MWun-S)of abandoned gray cast iron guide rail,inspired by the bionic theory,varying forms of bionic units such as spot(Sp-S),striation(St-S),and reticulation(Re-S)were fabricated on RQS of gray cast iron through laser processing technology.Firstly,the microstructure,phase composition,and microhardness of bionic units and RQS were analyzed by optical microscopy as well as X-ray diffraction instrument and scanning electron microscopy,respectively.Secondly,the oil lubrication wear experiment was performed on homemade line reciprocating wear machine.The results demonstrated that the bionic units had a significant effect on improving wear resistance of RQS of abandoned guide rail due to the microstructure and higher hardness.In addition,the weight loss ratios of MWun-S,Sp-S,St-S,and Re-S samples were decreased by 36.72%,36.78%,62.26%,and 80.39%,respectively,compared with that of SWun-S sample.The mechanism of wear resistance enhancement was also discussed.
基金This work is supported by the National Key R&D Program of China(Nos.2019YFA0307800,2017YFA0206302,and 2017YFA0206200)the National Natural Science Foundation of China(NSFC)(Nos.11974357,U1932151,and 51627801)+4 种基金G.Y.and X.H.thank the financial supports from the National Natural Science Foundation of China(NSFC)(No.11874409)This work is supported by the National Natural Science Foundation of China(NSFC)(Nos.61574060,and 8206300210)T.Y.acknowledges supports from the Major Program of Aerospace Advanced Manufacturing Technology Research Foundation NSFC and CASC,China(No.U1537204)Z.H.acknowledges the support from the Program of State Key Laboratory of Quantum Optics and Quantum Optics Devices(No.KF201816)The authors appreciate the help of Dr.Binbin Jiang in obtaining the HAADF-STEM images.
文摘Although many emerging new phenomena have been unraveled in two dimensional(2D)materials with long-range spin orderings,the usually low critical temperature in van der Waals(vdW)magnetic material has thus far hindered the related practical applications.Here,we show that ferromagnetism can hold above 300 K in a metallic phase of 1T-CrTe2 down to the ultra-thin limit.It thus makes CrTe2 so far the only known exfoliated ultra-thin vdW magnets with intrinsic long-range magnetic ordering above room temperature.An in-plane room-temperature negative anisotropic magnetoresistance(AMR)was obtained in ultra-thin CrTe2 devices,with a sign change in the AMR at lower temperature,with−0.6%and+5%at 300 and 10 K,respectively.Our findings provide insights into magnetism in ultra-thin CrTe2,expanding the vdW crystals toolbox for future room-temperature spintronic applications.
基金Acknowledgements The authors would like to acknowledge the support of the National Natural Science Foundation of China （NSFC） （Grant No. 61435006） and the Program for New Century Excellent Talents in University （NCET-12-0679） in China.
文摘An in-band optical signal-to-noise ratio （OSNR） monitoring technique with high resolution and large measurement range is demonstrated based on low- bandwidth coherent receiver and a tunable laser. The measurement range of OSNR is from 10 to 25 dB and the resolution can be controlled about ±1 dB.
