# Surface and Interface Modulation of V2O5/Ni(OH)2 Nanomaterials for Enhanced Alkaline Water Splitting

## TL;DR

This study develops a V2O5/Ni(OH)2 nanomaterial that improves water splitting efficiency in alkaline conditions, showing strong potential for practical energy applications.

## Contribution

A novel V2O5/Ni(OH)2 composite structure is synthesized and shown to enhance bifunctional electrocatalytic activity for water splitting.

## Key findings

- The catalyst achieves 89.6 mV overpotential for HER at −10 mA cm−2 in 1.0 M KOH.
- It requires 198 mV overpotential for OER at 10 mA cm−2 with stability at high current densities.
- The dual-electrode system needs only 2.82 V to reach 100 mA cm−2 current density.

## Abstract

To optimize the electrocatalytic reaction process through the synergistic effects of V and Ni, this study employed a two-step hydrothermal method to successfully construct a V2O5 composite structure grown on a Ni(OH)2 substrate (denoted V2O5/Ni(OH)2-2). Electrochemical evaluation revealed that this catalyst exhibits efficient bifunctional activity in 1.0 M KOH electrolyte. For the hydrogen evolution reaction (HER), it requires a mere 89.6 mV overpotential to achieve a current density of −10 mA cm−2. The catalyst also demonstrates excellent performance in the oxygen evolution reaction (OER), demanding only 198 mV overpotential to drive a current density of 10 mA cm−2, while maintaining low overpotential increases even at high current densities. Furthermore, it exhibits outstanding long-term stability during a 12 h continuous test. When assembled as a dual-electrode overall water splitting device, the system requires a voltage of only 2.82 V to drive a high current density of 100 mA cm−2, showcasing its significant potential for practical applications.