Enhanced photoelectrocatalytic performance of porphyrin-modified nickel cobaltite for methanol oxidation under visible light

Abstract

Rational design of efficient and durable non-precious metal electrocatalysts for methanol oxidation reaction (MOR) is a challenge of current research. In this work, the photosensitive organic molecule 5,10,15,20-tetrakis (4-carboxyphenyl) porphyrin (TCPP) has been used to modify nickel cobaltite (NiCo2O4) nanomaterials. Under visible light irradiation, its catalytic performance for MOR is better than that of pure NiCo2O4. The photoelectrocatalytic mechanism of TCPP/NiCo2O4 is attributed to the effective inhibition of photoelectron and hole recombination and then accelerated electron transfer, which are verified by photoluminescence (PL) emission spectra, impedance spectroscopy (EIS) and photocurrent response curves. Notably, the mass activity of TCPP/NiCo2O4 for MOR under visible light irradiation is 299.2 mA mg−1, higher than that of pure NiCo2O4 under dark (51.2-fold) and under visible light (36.5-fold). This study is very meaningful for the development of efficient noble-metal free photoelectrocatalysts for MOR.