Optimizing Formation\nEnergy Barrier of NiCo-LDH Cocatalyst\nto Enhance Photoelectrochemical Benzyl Alcohol Oxidation

Using organic oxidation reactions\nto replace the oxygen\nevolution\nreaction is a promising approach for producing high-value organic\nproducts and hydrogen. Here, we report a photoelectrochemical benzyl\nalcohol oxidation system based on an α-Fe<sub>2</sub>O<sub>3</sub> photoanode coated with a NiCo-layered double hydroxide (NiCo-LDH)\ncocatalyst. By adjustment of the relative content of Ni and Co in\nthe NiCo-LDH, the optimized photoanode achieved a benzyl alcohol conversion\nefficiency of 99.1% and benzoic acid selectivity of 90.9%. Experimental\nstudies revealed that the benzyl alcohol oxidation reaction proceeds\nvia an indirect catalytic mechanism involving high-valence species\nof the NiCo-LDH cocatalyst. Co in NiCo-LDH reduced the formation\nenergy barrier and oxidative capability of the high-valence species,\nthereby influencing the performance of the photoanode. This work provides\ninsights into the crucial role of cocatalyst composition in organic\nreaction oxidation and contributes to developing various photoelectrochemical\norganic oxidation systems.