Providing efficient charge transfer through the interface between the semiconductor and co-catalyst is greatly desired in photoelectrocatalytic (PEC) energy conversion.Herein,we excogitate a novel and facile means,via...Providing efficient charge transfer through the interface between the semiconductor and co-catalyst is greatly desired in photoelectrocatalytic (PEC) energy conversion.Herein,we excogitate a novel and facile means,via electrochemical activation,to successfully load the amorphous CoOOH layer architecture onto the surface of TiO_(2).Intriguingly,the as-obtained 6%CoOOH-TiO_(2)photoelectrode manifests optimal PEC performance with a high photocurrent density of 1.3 mA/cm~2,3.5 times higher than that of pristine TiO_(2).Electrochemical impedance spectroscopy (EIS),Tafel analysis and cyclic voltammetry (CV) methods show that the carrier transfer barrier within the electrode and the transition of Co^(3+)OOH to Co^(4+)OOH have the dominating effects on the PEC performance.Theoretical calculation reveals that the interface between the CoOOH and TiO_(2)improves the homogeneity of effective d-orbital electronic-transfer ability among Co sites.This research sheds light on the water oxidation reaction and the design of more favorable PEC cocatalysts.展开更多
Nickel oxides and(oxy)hydroxides are promising replacements for noble-metal-based catalysts owing to their high activity and good long-term stability for the oxygen evolution reaction(OER). Herein, we developed nanopo...Nickel oxides and(oxy)hydroxides are promising replacements for noble-metal-based catalysts owing to their high activity and good long-term stability for the oxygen evolution reaction(OER). Herein, we developed nanoporous Ni by a method of combined rapid solidification and chemical dealloying. Subsequently,nanoporous Ni O was obtained via heating treatment, the macropore and skeleton sizes of the NiO originated from Ni10Al90 alloy are 100–300 nm and 80–200 nm, respectively. Benefiting from the multi-stage nanoporous structure and high specific surface area, the nanoporous NiO demonstrates an outstanding OER, reaching 20 mA cm-2 at an overpotential of 356 mV in 1 M KOH. The corresponding Tafel slope and apparent activation energy are measured to be 76.73 mV dec-1 and 29.0 kJ mol-1, respectively. Moreover,kinetic analysis indicates that the Ni O catalyst shows pseudocapacitive characteristics, and the improved current is attributed to the high-rate pseudocapacitive behavior that efficiently maintains increased nickel redox cycling to accelerate the reaction rates. After 1000 cycles of voltammetry, the overpotential of the NiO decreases by 22 mV(j = 10 mA cm-2), exhibiting excellent stability and durability.展开更多
基金support from the National Key Research Program of China (2017YFA0204800, 2016YFA0202403)the Natural Science Foundation of China (No. 21603136)+3 种基金the Changjiang Scholar and Innovative Research Team (IRT_14R33)the Fundamental Research Funds for the Central Universities (GK202003042)The 111 Project (B14041)the Chinese National 1000-Talent-Plan program are also acknowledged。
文摘Providing efficient charge transfer through the interface between the semiconductor and co-catalyst is greatly desired in photoelectrocatalytic (PEC) energy conversion.Herein,we excogitate a novel and facile means,via electrochemical activation,to successfully load the amorphous CoOOH layer architecture onto the surface of TiO_(2).Intriguingly,the as-obtained 6%CoOOH-TiO_(2)photoelectrode manifests optimal PEC performance with a high photocurrent density of 1.3 mA/cm~2,3.5 times higher than that of pristine TiO_(2).Electrochemical impedance spectroscopy (EIS),Tafel analysis and cyclic voltammetry (CV) methods show that the carrier transfer barrier within the electrode and the transition of Co^(3+)OOH to Co^(4+)OOH have the dominating effects on the PEC performance.Theoretical calculation reveals that the interface between the CoOOH and TiO_(2)improves the homogeneity of effective d-orbital electronic-transfer ability among Co sites.This research sheds light on the water oxidation reaction and the design of more favorable PEC cocatalysts.
基金the funding support from the National Natural Science Foundation of China(No.51661018)the support from National Key Research Program of China(2017YFA0204800,2016YFA0202403)+3 种基金Natural Science Foundation of China(No.21603136)the National Science Basic Research Plan in Shaanxi Province of China(2017JM2007)the Changjiang Scholar and Innovative Research Team(IRT_14R33)The 111 Project(B14041)。
文摘Nickel oxides and(oxy)hydroxides are promising replacements for noble-metal-based catalysts owing to their high activity and good long-term stability for the oxygen evolution reaction(OER). Herein, we developed nanoporous Ni by a method of combined rapid solidification and chemical dealloying. Subsequently,nanoporous Ni O was obtained via heating treatment, the macropore and skeleton sizes of the NiO originated from Ni10Al90 alloy are 100–300 nm and 80–200 nm, respectively. Benefiting from the multi-stage nanoporous structure and high specific surface area, the nanoporous NiO demonstrates an outstanding OER, reaching 20 mA cm-2 at an overpotential of 356 mV in 1 M KOH. The corresponding Tafel slope and apparent activation energy are measured to be 76.73 mV dec-1 and 29.0 kJ mol-1, respectively. Moreover,kinetic analysis indicates that the Ni O catalyst shows pseudocapacitive characteristics, and the improved current is attributed to the high-rate pseudocapacitive behavior that efficiently maintains increased nickel redox cycling to accelerate the reaction rates. After 1000 cycles of voltammetry, the overpotential of the NiO decreases by 22 mV(j = 10 mA cm-2), exhibiting excellent stability and durability.
