Bifunctional Electrocatalysts Based on Mo-Doped NiCoP Nanosheet Arrays for Overall Water Splitting

Highlights

• Freestanding Mo-doped NiCoP nanosheets are designed as bifunctional electrocatalysts for overall water splitting.

• Remarkable electrocatalytic performances are achieved by Mo doping, where a low-water-splitting voltage of 1.61 V at 10 mA cm ⁻² is obtained.

Electronic supplementary material

The online version of this article (10.1007/s40820-019-0289-6) contains supplementary material, which is available to authorized users.

Abstract

Rational design of efficient bifunctional electrocatalysts is highly imperative but still a challenge for overall water splitting. Herein, we construct novel freestanding Mo-doped NiCoP nanosheet arrays by the hydrothermal and phosphation processes, serving as bifunctional electrocatalysts for overall water splitting. Notably, Mo doping could effectively modulate the electronic structure of NiCoP, leading to the increased electroactive site and improved intrinsic activity of each site. Furthermore, an electrochemical activation strategy is proposed to form Mo-doped (Ni,Co)OOH to fully boost the electrocatalytic activities for oxygen evolution reaction. Benefiting from the unique freestanding structure and Mo doping, Mo-doped NiCoP and (Ni,Co)OOH show the remarkable electrochemical performances, which are competitive among current researches. In addition, an overall water splitting device assembled by both electrodes only requires a cell voltage of 1.61 V to reach a current density of 10 mA cm ⁻². Therefore, this work opens up new avenues for designing nonprecious bifunctional electrocatalysts by Mo doping and in situ electrochemical activation.

Electronic supplementary material

The online version of this article (10.1007/s40820-019-0289-6) contains supplementary material, which is available to authorized users.