Enhancing hydrogen evolution reaction efficiency with electrospun Ni-doped Zn(O,S) microfibers photocatalyst: A novel approach for sustainable energy conversion

This study presents Ni-doped Zn(O,S) microfibers as an effective photocatalyst for addressing global energy and environmental challenges by producing green hydrogen as a sustainable alternative to fossil fuels. In addition, the embedment of nanocatalyst into PVP fibers also mitigates the harmful of nanoparticle leaching. Ni-doped Zn(O,S) microfiber photocatalysts with varying Ni concentrations were effectively produced using a simple electrospinning technique, followed by annealing at 180 °C for 3 h. The optimized ZN-2.5 microfiber photocatalyst has achieved the highest hydrogen (H₂) production rate of 648.2 μmmol g⁻¹ h⁻¹. ZN-2.5 has recorded 3240.5 μmmol g⁻¹ of hydrogen generation rate after 5 h of illumination in addition to extraordinary stability up to 30 h. This work demonstrates the significant improvement of the overall photocatalytic H₂ evolution reaction (HER) process over ZN-X catalysts via doping small amounts of Ni to the Zn(O,S) matrix. Ni doping increases the microfibers light absorbance ability, improves charge separation transfer, and minimizes the recombination rate of the photogenerated electron-hole pairs. Moreover, Ni-doped Zn(O,S) achieved unique stability up to 7 runs for photocatalytic H₂ production. More oxygen vacancies are formed on the surface of the photocatalyst upon illumination thus showing elevating activity while recycling the photocatalyst. The reported photocatalysts in this paper are low-cost, earth-abundant, and environment-friendly which is encouraging to design more novel photocatalysts following the same trend.