A low-cost strategy for photocatalytic hydrogen production by using non-noble metal catalysts and biomass as a sacrificial agent

Abstract

In recent years, photocatalytic hydrogen production using biomass as a sacrificial agent has emerged as a promising strategy for renewable energy conversion. However, most reported studies still rely on expensive noble metal catalysts, and raw biomass typically exhibits low surface activity, which limits its practical application. In this study, the effects of different factors on photocatalytic hydrogen production were investigated using urea-treated corn straw as the sacrificial agent and non-noble metal composite materials as catalysts. The impact of straw biomass under different treatment conditions was also studied. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and high-performance liquid chromatography (HPLC) were employed to characterize the composition, structure, and morphology of the catalyst and corn straw. The Cu(OH)₂–Ni(OH)₂/TiO₂ composite catalyst with an optimal Cu : Ni ratio of 4 : 1 and a total metal hydroxide loading of 0.5 wt% was synthesized via chemical deposition. Moreover, the urea treatment of corn straw was optimized, effectively removing lignin, disrupting the dense fiber structure, and introducing nitrogen-containing electron-donating groups to enhance surface activity. Under the optimal conditions, the hydrogen production reached 108.37 μmol after 4 h, corresponding to a 60% increase compared to the 67.72 μmol obtained using untreated corn straw. Furthermore, the catalytic efficiency of the non-noble metal catalyst reached 85% of that of 0.5 wt%Pt/TiO₂ with the same loading rate. This strategy, which combines non-noble metal photocatalysts with natural biomass sacrificial agents, greatly reduces cost and environmental pollution and represents a promising research direction.