Considering photocatalytic activity of Cu/biochar-doped TiO using corn straw as sacrificial agent in water decomposition to hydrogen.

In this paper, a simple one-pot thermal synthesis method was used to successfully prepare Cu/biochar-doped TiO composite catalytic materials. The photocatalytic hydrogen production performance of the composites under different environmental conditions (dark, solar, and visible light irradiation) was analyzed in a biomass photocatalytic system using a corn straw suspension as a sacrificial agent. The Cu/biochar-doped TiO materials were characterized by SEM, TEM, XRD, FT-IR, XPS, and UV analysis. The photoelectric properties of the Cu/biochar-doped TiO composites were also analyzed, and the charge separation mechanism of photogenerated carriers under different environmental conditions was investigated. Compared with pure TiO, the hydrogen production rate of Cu/biochar-doped TiO is 23.6 times higher under visible light irradiation and 16.8 times higher under simulated solar irradiation. Using density functional theory, a crystal structure model of Cu/biochar-doped TiO was established to analyze its energy band structure and density of states. An analysis of the mechanism shows that under simulated sunlight irradiation, the synergistic effect of the TiO doped with Cu and biochar causes the formation of a potential Schottky heterojunction on the surface and induces interfacial charge transfer. Furthermore, under visible light irradiation, the photocatalytic production of hydrogen by the Cu/biochar-doped TiO composite is mainly due to the surface plasmon resonance mechanism of Cu ion-doped TiO.