Sprout-shaped Mo-doped CoP with maximized hydrophilicity and gas bubble release for high-performance water splitting catalyst

Abstract

The electrochemical water splitting reaction offers an attractive approach to generate hydrogen fuels as green and renewable energy, in helping ease the global warming and energy crisis, working as a clean energy carrier. In this study, we present the sprout-shaped Mo-doped CoP (denoted CP) as a catalyst for efficient water splitting electrode under alkaline environment. The electrode possesses a unique nanoarray type ‘pillar’ and microscale ‘tip’ structure, which promotes high hydrophilicity and effective gas bubble release, hence achieving a future goal of highly efficient water splitting device for practical use. For both hydrogen and oxygen evolution reaction (HER and OER), the electrode shows remarkable catalytic activity together with reliable stability in alkaline solution, which makes CP a promising electrocatalyst to date. By investigating the gas releasing efficiency regarding various nano/microstructured electrodes, as-prepared CP surpasses the compared samples, indicating maximized nano/microstructures specialized for gas evolution electrode. When the CP performedas an overall water splitting electrode, only 1.49 V of overpotential is needed to achieve the current density of 10 mA·cm−2 and maintained 10 and 200 mA·cm−2 for over 35 h with little degradation of catalytic activity. This work would give inspiration to many investigators who work on optimizing structures of transition metal-based nanomaterials, promoting their applications in other renewable energy options.