Synthesis of bifunctional NiFe layered double hydroxides (LDH)/Mo-doped g-C3N4 electrocatalyst for efficient methanol oxidation and seawater splitting

Chemosphere. 2023 Jan;312(Pt 1):137203. doi: 10.1016/j.chemosphere.2022.137203. Epub 2022 Nov 11.

Abstract

To boost the oxygen evolution reaction (OER) and methanol oxidation reaction (MOR) of pristine NiFe-layered double hydroxides (LDH), the NiFe-LDH/Mo-doped graphitic carbon nitride (NiFe-LDH/MoCN) heterojunction was synthesized herein through hydrothermal method. The establishment of built-in electric field in NiFe-LDH/MoCN heterojunction enhanced the electrochemical oxidation activities towards both seawater splitting and methanol oxidation, via the improving electrocatalyst surface wettability and conductivity. Almost 10-fold enhancement of turnover frequency (TOF) and electrochemical active surface area (ECSA) than pure NiFe-LDH implied more active sites to participate in catalytic reactions via Mo doping and the formation of heterostructure. Moreover, the local charge redistribution demonstrated in the NiFe-LDH/MoCN interface region may favor the adsorption of methanol and OH- in the seawater. The present work may expound the strong coupling interaction and the establishment of built-in electric field in the interface between NiFe-LDH and semiconductor to enhance both methanol oxidation and seawater oxidation for NiFe-LDH.

Keywords: Built-in electric field; Methanol oxidation reaction (MOR); Mo-doped g-C(3)N(4); NiFe layered Double hydroxides (LDH); Oxygen evolution reaction (OER); Seawater.