Electrocatalytic nitrate(NO_(3)^(−))reduction to ammonia(NH_(3))offers a viable approach for sustainable NH_(3)production and environmental denitrification.Copper(Cu)possesses a distinctive electronic structure,which ...Electrocatalytic nitrate(NO_(3)^(−))reduction to ammonia(NH_(3))offers a viable approach for sustainable NH_(3)production and environmental denitrification.Copper(Cu)possesses a distinctive electronic structure,which can augment the reaction kinetics of NO_(3)^(−)and impede hydrogen evolution reaction(HER),rendering it a promising contender for the electrosynthesis of NH_(3)from NO_(3)^(−).Nevertheless,the role of Cu_(2)O in copper-based catalysts still requires further investigation for a more comprehensive understanding.Herein,the Cu_(2)O/Cu(OH)_(2)heterostructures are successfully fabricated through liquid laser irradiation using CuO nanoparticles as a precursor.Experimental and theoretical researches reveal that Cu_(2)O/Cu(OH)_(2)heterostructure exhibits enhanced electrocatalytic performance for NO_(3)^(−)to NH_(3)because Cu(OH)_(2)promotes electron transfer and reduces the valence state of Cu active site in Cu_(2)O.At−0.6 V(vs.reversible hydrogen electrode(RHE)),the NH_(3)yield reaches its maximum at 1630.66±29.72μg·h^(−1)·mgcat^(−1),while the maximum of Faraday efficiency(FE)is 76.95%±5.51%.This study expands the technical scope of copper-based catalyst preparation and enhances the understanding of the electrocatalytic mechanism of NO_(3)^(−)to NH_(3).展开更多
Developing efficient and promising non-noble catalysts for oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) is vital but still a huge challenge for the clean energy system. Herein, we have integrate...Developing efficient and promising non-noble catalysts for oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) is vital but still a huge challenge for the clean energy system. Herein, we have integrated the active components for OER(Ni(OH)_(2)) and HER(Ni S_(2) and Ni(OH)_(2)) into Ni(OH)_(2)@NiS_(2) heterostructures by a facile reflux method. The in-situ formed Ni(OH)_(2) thin layer is coated on the surface of hollow Ni S2 nanosphere. The uniform Ni(OH)_(2)@NiS_(2) hollow sphere processes enlarge the electrochemically active specific surface area and enhance the intrinsic activity compared to NiS_(2) precursor, which affords a current density of 10 m A cm^(-2) at the overpotential of 309 m V and 100 m Acm^(-2) at 359 m V for OER. Meanwhile, Ni(OH)_(2)@NiS_(2) can reach 10 m A cm^(-2) at 233 m V for HER, superior to pure NiS_(2). The enhanced performance can be attributed to the synergy between Ni(OH)_(2) and NiS_(2). Specifically, Ni(OH)_(2) has three functions for water splitting: providing active sites for hydrogen adsorption and hydroxyl group desorption and working as real OER active sites. Moreover, Ni(OH)_(2)@NiS_(2) displays great stability for OER(50 h) and HER(30 h).展开更多
基金Scientific Research Project in Anhui Jianzhu University(No.2023QDZ04).
文摘Electrocatalytic nitrate(NO_(3)^(−))reduction to ammonia(NH_(3))offers a viable approach for sustainable NH_(3)production and environmental denitrification.Copper(Cu)possesses a distinctive electronic structure,which can augment the reaction kinetics of NO_(3)^(−)and impede hydrogen evolution reaction(HER),rendering it a promising contender for the electrosynthesis of NH_(3)from NO_(3)^(−).Nevertheless,the role of Cu_(2)O in copper-based catalysts still requires further investigation for a more comprehensive understanding.Herein,the Cu_(2)O/Cu(OH)_(2)heterostructures are successfully fabricated through liquid laser irradiation using CuO nanoparticles as a precursor.Experimental and theoretical researches reveal that Cu_(2)O/Cu(OH)_(2)heterostructure exhibits enhanced electrocatalytic performance for NO_(3)^(−)to NH_(3)because Cu(OH)_(2)promotes electron transfer and reduces the valence state of Cu active site in Cu_(2)O.At−0.6 V(vs.reversible hydrogen electrode(RHE)),the NH_(3)yield reaches its maximum at 1630.66±29.72μg·h^(−1)·mgcat^(−1),while the maximum of Faraday efficiency(FE)is 76.95%±5.51%.This study expands the technical scope of copper-based catalyst preparation and enhances the understanding of the electrocatalytic mechanism of NO_(3)^(−)to NH_(3).
基金financially supported by the National Natural Science Foundation of China (52174283)。
文摘Developing efficient and promising non-noble catalysts for oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) is vital but still a huge challenge for the clean energy system. Herein, we have integrated the active components for OER(Ni(OH)_(2)) and HER(Ni S_(2) and Ni(OH)_(2)) into Ni(OH)_(2)@NiS_(2) heterostructures by a facile reflux method. The in-situ formed Ni(OH)_(2) thin layer is coated on the surface of hollow Ni S2 nanosphere. The uniform Ni(OH)_(2)@NiS_(2) hollow sphere processes enlarge the electrochemically active specific surface area and enhance the intrinsic activity compared to NiS_(2) precursor, which affords a current density of 10 m A cm^(-2) at the overpotential of 309 m V and 100 m Acm^(-2) at 359 m V for OER. Meanwhile, Ni(OH)_(2)@NiS_(2) can reach 10 m A cm^(-2) at 233 m V for HER, superior to pure NiS_(2). The enhanced performance can be attributed to the synergy between Ni(OH)_(2) and NiS_(2). Specifically, Ni(OH)_(2) has three functions for water splitting: providing active sites for hydrogen adsorption and hydroxyl group desorption and working as real OER active sites. Moreover, Ni(OH)_(2)@NiS_(2) displays great stability for OER(50 h) and HER(30 h).
