Exploring Zn doped NiBP microspheres as efficient and stable electrocatalyst for industrial-scale water splitting

Green hydrogen holds great promise for the future energy ecosystem and designing alternative electrocatalysts is essential for industrial-scale green hydrogen production for high-current water splitting under industrial conditions. Herein, the Zn-doped NiBP microsphere electrocatalyst is fabricated via a multi-step process combining hydrothermal and electrochemical approaches, followed by post-annealing. The optimized Zn/NiBP electrode outperforms the majority of previously reported catalysts, with low overpotentials of 95 ​mV for HER (hydrogen evolution reaction) and 280 ​mV for OER (oxygen evolution reaction) at 100 ​mA ​cm⁻² in 1 ​mol ​L⁻¹ KOH. The bifunctional Zn/NiBP || Zn/NiBP demonstrates a 3.10 ​V cell voltage at 2000 ​mA ​cm⁻² in 1 ​mol ​L⁻¹ KOH, surpassing the benchmark Pt/C || RuO₂ systems. The Pt/C || Zn/NiBP hybrid system exhibits exceptionally low cell voltages of 2.50 and 2.30 ​V at 2000 ​mA ​cm⁻² in 1 and 6 ​mol ​L⁻¹ KOH respectively, demonstrating excellent overall water-splitting performance under challenging industrial conditions. Furthermore, the 2-E system shows remarkable stability over 120 ​h at 1000 ​mA ​cm⁻² in 1 and 6 ​mol ​L⁻¹ KOH, indicating the robust anti-corrosion properties of the Zn/NiBP microspheres. Zn-doped NiBP microspheres exhibit enhanced electrochemical conductivity, active surface area and intrinsic electrocatalytic activity due to synergistic interactions among Zn, Ni, B and P, enabling rapid charge transfer and superior electrocatalytic performance for efficient hydrogen generation.