An efficient hole transfer pathway on hematite integrated by ultrathin Al2O3 interlayer and novel CuCoOx cocatalyst for efficient photoelectrochemical water oxidation

摘要

Highly photoelectrochemical water oxidation efficiency could be realized by means of efficient photogenerated holes transfer pathway and low-cost cocatalysts. Here, we have integrated an ultrathin Al2O3 layer and novel copper-cobalt oxide (CuCoOx) cocatalyst on alpha-Fe2O3 photo-anode to construct unobstructed holes transfer pathway and improve PEC activity. The resultant alpha-Fe2O3/Al2O3/CuCoO x photoanode exhibits high photocurrent density of 2.23 mA/cm(2) at 1.23 V versus the reversible hydrogen electrode (V RHE ) and negative onset potential of 0.7 VRETE, which is about 17.6 times higher and 200 mV cathodic shift than bare alpha-Fe2O3 nanorod arrays. Detailed experimental results indicate the surface recombination passivation function of Al2O3 layer and improvement in charge separation and transfer kinetics of the role of low overpotential of CuCoOx with abundant oxygen vacancies for OER. The comparison discussion with CoOx and CuOx oxygen evolution catalysts (OECs) further illustrates the excellent catalytic performance of the CuCoOx. This work points to the effective utilization of novel but cheap CuCoOx OECs on photoanodes and provides a strategy for designing high activity photoanodes in photoelectrochemical water oxidation.