Stable p-Type Molybdenum and Copper Ion-Containing Coordination Polymer Photocathode in Protic Electrolytes

Abstract

Photoelectro-redox catalysts for multiproton-coupled electron transfer are vital for photo-assisted electrochemical energy conversion and electrosynthetic processes. Herein, we describe a facile method for the preparation of the molybdenum and copper ion-containing coordination polymer using a bridging functional triazine ligand. X-ray photoelectron spectroscopy (XPS) analysis reveals the presence of mixed-valent molybdenum and copper ions in the coordination polymer. In contrast to the p-type copper oxide photocathode, this photocathode material displays excellent photoelectrochemical stability in strong protic electrolytes. High photocurrent responses were observed for the molybdenum and copper ions-incorporated metallopolymers and nearly 20 times higher acidic pH than in a neutral electrolyte. The constant-potential photocurrent measurements in protic electrolytes for a longer duration display a stable p-type response of nearly 50–60 μA cm–2. The photoelectrocatalyst exhibits an improved electrochemical oxygen reduction and carbon dioxide reduction.