Electrochemical nitrogen looping represents a promising carbon-free and sustainable solution for the energy transition,in which electrochemical ammonia oxidation stays at the central position.However,the various nitro...Electrochemical nitrogen looping represents a promising carbon-free and sustainable solution for the energy transition,in which electrochemical ammonia oxidation stays at the central position.However,the various nitrogen-containing intermediates tend to poison and corrode the electrocatalysts,even the state-of-the-art noble-metal ones,which is worsened at a high applied potential.Herein,we present an ultrarapid laser quenching strategy for constructing a corrosion-resistant and nanostructured CuNi alloy metallic glass electrocatalyst.In this material,single-atom Cu species are firmly bonded with the surrounding Ni atoms,endowing exceptional resistance against ammonia corrosion relative of conventional CuNi alloys.Remarkably,a record-high durability for over 300 h is achieved.Ultrarapid quenching also allows a much higher Cu content than typical single-atom alloys,simultaneously yielding a high rate and selectivity for ammonia oxidation reaction(AOR).Consequently,an outstanding ammonia conversion rate of up to 95%is achieved with 91.8%selectivity toward nitrite after 8 h.Theoretical simulations reveal that the structural amorphization of CuNi alloy could effectively modify the electronic configuration and reaction pathway,generating stable singleatom Cu active sites with low kinetic barriers for AOR.This ultrarapid laser quenching strategy thus provides a new avenue for constructing metallic glasses with well-defined nanostructures,presenting feasible opportunities for performance enhancement for AOR and other electrocatalytic processes.展开更多
Modulating the adsorption energy of intermediate species via alloying presents a promising approach to enhance the electrocatalytic nitrate reduction to ammonia(NRA).Nonetheless,the synthesis of alloy catalysts that a...Modulating the adsorption energy of intermediate species via alloying presents a promising approach to enhance the electrocatalytic nitrate reduction to ammonia(NRA).Nonetheless,the synthesis of alloy catalysts that are uniformly distributed and structurally stable poses significant challenges.Herein,the CuNi alloy was successfully anchored on oxygen vacancy-rich N-Ti_(3)C_(2)T_(x) through metal-support interactions(MSI).The three-dimensional(3D)wrinkled morphology of N-Ti_(3)C_(2)T_(x) MXene was achieved by employing melamine-formaldehyde spheres(MFs)as self-sacrificial templates,which effectively prevented the restacking of the Ti_(3)C_(2)T_(x) layers,thereby increasing specific surface area and promoting the formation of surface oxygen vacancies.Ti–O–M structure plays a crucial role in inhibiting both particle migration and metal atom diffusion.X-ray photoelectron spectroscopy(XPS)analysis confirms moderate metal-support interactions between the CuNi alloy and N-Ti_(3)C_(2)T_(x),leading to the establishment of stable Ti–O–M bonds and charge redistribution within the Ti-O-M framework.The Cu_(5)Ni_(5)/N-Ti_(3)C_(2)T_(x) sample achieves an impressive Faradaic efficiency(FE)of 97.50%at−0.27 V vs.RHE,alongside the highest NH3 yield rate of 527.44µmol h−1 cm−2.In-situ electrochemical Raman spectroscopy and theoretical calculations reveal that the high intrinsic catalytic activity of NRA can be attributed to the synergistic effects between the CuNi alloy and the interfacial metal-oxygen interactions.This work provides significant perspectives on the design of interfacial metal interactions and the development of durable electrocatalysts.展开更多
Photocatalytic H_(2) production from an aqueous NH_(3) solution is an emerging and potential way to pu-rify wastewater and obtain green energy.However,the H_(2) production rate by semiconductors is largely limited by ...Photocatalytic H_(2) production from an aqueous NH_(3) solution is an emerging and potential way to pu-rify wastewater and obtain green energy.However,the H_(2) production rate by semiconductors is largely limited by the fast recombination of photogenerated charges and the weak H+adsorption ability.Herein,non-noble bimetallic CuNi cocatalyst was deposited on the surface of TiO_(2) nanofiber to prepare CuNi/TiO_(2) composites via simple hydrothermal procedure followed by calcination treatment.The obtained CuNi/TiO_(2) composites not only improve the absorption and utilization abilities of incident light,but also offer plen-tiful active sites and inhibit the recombination of charges.As a result,the photocatalytic efficiency of H_(2) production is much higher than that of pure TiO_(2) in low concentration ammonia solution.Particularly,the Cu_(2) Ni_(1)/TiO_(2) sample exhibits the maximum H_(2) production rate(285.4μmol h^(-1) g^(-1)),which was 4.0,2.1 and 6.7 times higher than that of Cu/TiO_(2),Ni/TiO_(2) and pure TiO_(2) nanofiber,respectively.This yield also outperforms Pt/TiO_(2) in terms of its performance.Meanwhile,the oxidation product of hydrazine hydrate is detected.Furthermore,density-functional-theory(DFT)calculations reveal that the synergistic effect of bimetallic CuNi alloy benefits to H^(∗)sorption and promotes H_(2) desorption,thus resulting in the improvement of H_(2) production.This work provides new insight into the fabrication of non-noble metal alloys as efficient cocatalysts for photocatalysis.展开更多
基金National Natural Science Foundation of China,Grant/Award Numbers:22179093,22379111Department of Education of Guangdong Province for Higher Educational Institution,Grant/Award Number:2022ZDZX4104Shenzhen General Project for Institutions of Higher Education,Grant/Award Number:20231127113219001。
文摘Electrochemical nitrogen looping represents a promising carbon-free and sustainable solution for the energy transition,in which electrochemical ammonia oxidation stays at the central position.However,the various nitrogen-containing intermediates tend to poison and corrode the electrocatalysts,even the state-of-the-art noble-metal ones,which is worsened at a high applied potential.Herein,we present an ultrarapid laser quenching strategy for constructing a corrosion-resistant and nanostructured CuNi alloy metallic glass electrocatalyst.In this material,single-atom Cu species are firmly bonded with the surrounding Ni atoms,endowing exceptional resistance against ammonia corrosion relative of conventional CuNi alloys.Remarkably,a record-high durability for over 300 h is achieved.Ultrarapid quenching also allows a much higher Cu content than typical single-atom alloys,simultaneously yielding a high rate and selectivity for ammonia oxidation reaction(AOR).Consequently,an outstanding ammonia conversion rate of up to 95%is achieved with 91.8%selectivity toward nitrite after 8 h.Theoretical simulations reveal that the structural amorphization of CuNi alloy could effectively modify the electronic configuration and reaction pathway,generating stable singleatom Cu active sites with low kinetic barriers for AOR.This ultrarapid laser quenching strategy thus provides a new avenue for constructing metallic glasses with well-defined nanostructures,presenting feasible opportunities for performance enhancement for AOR and other electrocatalytic processes.
基金upported by the National Natural Science Foundation of China(Nos.U22A20253,52272293,and 52401275)the Fellowship of China Postdoctoral Science Foundation(No.2021M701116).
文摘Modulating the adsorption energy of intermediate species via alloying presents a promising approach to enhance the electrocatalytic nitrate reduction to ammonia(NRA).Nonetheless,the synthesis of alloy catalysts that are uniformly distributed and structurally stable poses significant challenges.Herein,the CuNi alloy was successfully anchored on oxygen vacancy-rich N-Ti_(3)C_(2)T_(x) through metal-support interactions(MSI).The three-dimensional(3D)wrinkled morphology of N-Ti_(3)C_(2)T_(x) MXene was achieved by employing melamine-formaldehyde spheres(MFs)as self-sacrificial templates,which effectively prevented the restacking of the Ti_(3)C_(2)T_(x) layers,thereby increasing specific surface area and promoting the formation of surface oxygen vacancies.Ti–O–M structure plays a crucial role in inhibiting both particle migration and metal atom diffusion.X-ray photoelectron spectroscopy(XPS)analysis confirms moderate metal-support interactions between the CuNi alloy and N-Ti_(3)C_(2)T_(x),leading to the establishment of stable Ti–O–M bonds and charge redistribution within the Ti-O-M framework.The Cu_(5)Ni_(5)/N-Ti_(3)C_(2)T_(x) sample achieves an impressive Faradaic efficiency(FE)of 97.50%at−0.27 V vs.RHE,alongside the highest NH3 yield rate of 527.44µmol h−1 cm−2.In-situ electrochemical Raman spectroscopy and theoretical calculations reveal that the high intrinsic catalytic activity of NRA can be attributed to the synergistic effects between the CuNi alloy and the interfacial metal-oxygen interactions.This work provides significant perspectives on the design of interfacial metal interactions and the development of durable electrocatalysts.
基金financially supported by the National Natural Science Foundation of China(Nos.22108211,22478308,22478309,22272125,22402156,and 22409151)the Research and Innovation Initiatives of WHPU(No.2024Y18)the Key Research and De-velopment Project of Hainan Province(No.ZDYF2024GXJS005).
文摘Photocatalytic H_(2) production from an aqueous NH_(3) solution is an emerging and potential way to pu-rify wastewater and obtain green energy.However,the H_(2) production rate by semiconductors is largely limited by the fast recombination of photogenerated charges and the weak H+adsorption ability.Herein,non-noble bimetallic CuNi cocatalyst was deposited on the surface of TiO_(2) nanofiber to prepare CuNi/TiO_(2) composites via simple hydrothermal procedure followed by calcination treatment.The obtained CuNi/TiO_(2) composites not only improve the absorption and utilization abilities of incident light,but also offer plen-tiful active sites and inhibit the recombination of charges.As a result,the photocatalytic efficiency of H_(2) production is much higher than that of pure TiO_(2) in low concentration ammonia solution.Particularly,the Cu_(2) Ni_(1)/TiO_(2) sample exhibits the maximum H_(2) production rate(285.4μmol h^(-1) g^(-1)),which was 4.0,2.1 and 6.7 times higher than that of Cu/TiO_(2),Ni/TiO_(2) and pure TiO_(2) nanofiber,respectively.This yield also outperforms Pt/TiO_(2) in terms of its performance.Meanwhile,the oxidation product of hydrazine hydrate is detected.Furthermore,density-functional-theory(DFT)calculations reveal that the synergistic effect of bimetallic CuNi alloy benefits to H^(∗)sorption and promotes H_(2) desorption,thus resulting in the improvement of H_(2) production.This work provides new insight into the fabrication of non-noble metal alloys as efficient cocatalysts for photocatalysis.
