Electrochemical nitrate reduction reaction (NITRR) is regarded as a “two birds-one stone” method for the treatment of nitrate contaminant in polluted water and the synthesis of valuable ammonia, which is retarded by...Electrochemical nitrate reduction reaction (NITRR) is regarded as a “two birds-one stone” method for the treatment of nitrate contaminant in polluted water and the synthesis of valuable ammonia, which is retarded by the lack of highly reactive and selective electrocatalysts .Herein, for the first time, nickel foam supported Co_(4) N was designed as a high-performance NITRR catalyst by an in-situ nonmetal leaching-induced strategy.At the optimal potential, the Co_(4) N/NF catalyst achieves ultra-high Faraday efficiency and NH_(3) selectivity of 95.4% and 99.4%, respectively.Ex situ X-ray absorption spectroscopy (XAS), together with other experiments powerfully reveal that the nitrogen vacancies produced by nitrogen leaching are stable and play a key role in boosting nitrate reduction to ammonia.Theoretical calculations confirm that Co_(4) N with abundant nitrogen vacancies can optimize the adsorption energies of NO_(3)^(-) and intermediates, lower the free energy (Δ G ) of the potential-determining step (*NH_(3) to NH_(3) ) and inhibit the formation of N-containing byproducts.In addition, we also conclude that the nitrogen vacancies can stabilize the adsorbed hydrogen, making H_(2) quite difficult to produce, and lowering ΔG from *NO to *NOH, which facilitates the selective reduction of nitrate.This study reveals significant insights about the in-situ nonmetal leaching to enhance the NITRR activity.展开更多
Stabilizing black-phase formamidinium lead triiodide(FAPbI_(3))is critical for high-performance perovskite solar cells(PSCs).We present a stabilization strategy utilizing co-evaporated cesium lead iodide(CsPbI_(3))cap...Stabilizing black-phase formamidinium lead triiodide(FAPbI_(3))is critical for high-performance perovskite solar cells(PSCs).We present a stabilization strategy utilizing co-evaporated cesium lead iodide(CsPbI_(3))capping layers.Enabled by favorable crystal lattice matching,cubic-phase CsPbI_(3)spontaneously forms on FAPbI_(3)surfaces,establishing mutual phase stabilization with the underlying black-phase FAPbI_(3).When combined with ammonium salt interface modification,the CsPbI_(3)interlayer effectively suppresses the ion(FA^(+)and F-PEA^(+))diffusion between the stacked perovskite layers.The FAPbI_(3)/CsPbI_(3)bilayer structured devices exhibited a certified record reverse-scanning power-conversion efficiency of 27.17%and maintained a stabilized power output efficiency of 26.62%.Remarkably,the cells retain 93.5%of the initial efficiency after 1500 h damp-heat test,and retaining over 94.2%of its maximum PCE after about 1185 h with a linear extrapolation to a T90 of 2352 h operation under continuous illumination at maximum power point tracking at 85℃.展开更多
基金financial supports from National Natural Science Foundation of China(Nos.91741105,22006120)Program for Innovation Team Building at Institutions of Higher Education in Chongqing(No.CXTDX201601011)Chongqing Municipal Natural Science Foundation(No.cstc2018jcyjAX0625).
文摘Electrochemical nitrate reduction reaction (NITRR) is regarded as a “two birds-one stone” method for the treatment of nitrate contaminant in polluted water and the synthesis of valuable ammonia, which is retarded by the lack of highly reactive and selective electrocatalysts .Herein, for the first time, nickel foam supported Co_(4) N was designed as a high-performance NITRR catalyst by an in-situ nonmetal leaching-induced strategy.At the optimal potential, the Co_(4) N/NF catalyst achieves ultra-high Faraday efficiency and NH_(3) selectivity of 95.4% and 99.4%, respectively.Ex situ X-ray absorption spectroscopy (XAS), together with other experiments powerfully reveal that the nitrogen vacancies produced by nitrogen leaching are stable and play a key role in boosting nitrate reduction to ammonia.Theoretical calculations confirm that Co_(4) N with abundant nitrogen vacancies can optimize the adsorption energies of NO_(3)^(-) and intermediates, lower the free energy (Δ G ) of the potential-determining step (*NH_(3) to NH_(3) ) and inhibit the formation of N-containing byproducts.In addition, we also conclude that the nitrogen vacancies can stabilize the adsorbed hydrogen, making H_(2) quite difficult to produce, and lowering ΔG from *NO to *NOH, which facilitates the selective reduction of nitrate.This study reveals significant insights about the in-situ nonmetal leaching to enhance the NITRR activity.
基金supported by the National Key Research and Development Program of China[2022YFB4200305(X.L.,Y.R.,Z.X.and R.G.)]the National Natural Science Foundation of China[22279039(X.L.),52172200(Y.R.),52302254(R.G.)and 22209068(X.L)]+2 种基金the Innovation Project of Optics Valley Laboratory OVL2021BG008(X.L.)the Foundation of State Key Laboratory of New Textile Materials and Advanced Processing Technologies Grant F22021011(X.L.)the Guangdong Basic and Applied Basic Research Foundation(No.2025A1515012297).
文摘Stabilizing black-phase formamidinium lead triiodide(FAPbI_(3))is critical for high-performance perovskite solar cells(PSCs).We present a stabilization strategy utilizing co-evaporated cesium lead iodide(CsPbI_(3))capping layers.Enabled by favorable crystal lattice matching,cubic-phase CsPbI_(3)spontaneously forms on FAPbI_(3)surfaces,establishing mutual phase stabilization with the underlying black-phase FAPbI_(3).When combined with ammonium salt interface modification,the CsPbI_(3)interlayer effectively suppresses the ion(FA^(+)and F-PEA^(+))diffusion between the stacked perovskite layers.The FAPbI_(3)/CsPbI_(3)bilayer structured devices exhibited a certified record reverse-scanning power-conversion efficiency of 27.17%and maintained a stabilized power output efficiency of 26.62%.Remarkably,the cells retain 93.5%of the initial efficiency after 1500 h damp-heat test,and retaining over 94.2%of its maximum PCE after about 1185 h with a linear extrapolation to a T90 of 2352 h operation under continuous illumination at maximum power point tracking at 85℃.
