Cu-doped ZnCdS-based photocatalyst for efficient photocatalytic hydrogen production by photothermal assistance

In solar energy utilization, photocatalytic hydrogen production has been widely researched. To address issues such as low efficiency of photocatalysts, Cu-doped Zn0.5Cd0.5S composite photocatalysts were prepared using a hydrothermal method for photocatalytic hydrogen production. The Cu/Zn0.5Cd0.5S photocatalyst was characterized using XRD, XPS, SEM, TEM, UV–vis-DRS, fluorescence spectrophotometer, and electrochemical workstation. The results indicate that Cu doping alters the crystal and band structures of Zn0.5Cd0.5S. Hydrogen production experiments were conducted under xenon lamp irradiation, and at 45 °C, the highest hydrogen production rate was 2.72 and 1.63 times that of single Zn0.5Cd0.5S and Cu-doped Zn0.5Cd0.5S at room temperature (25 °C), respectively. Cu doping imparted a photothermal effect to the photocatalytic hydrogen production experiment, enhancing its efficiency.Cu doping captured electrons by replacing some Zn, constructing an internal electric field, forming defect energy levels, which hindered electron-hole recombination. Additionally, Cu ions acted as a plasma, inducing a plasma effect during hydrogen production, accelerating the rate of solar energy conversion to thermal energy, thus improving hydrogen production efficiency. This research not only provides a photocatalyst for photocatalytic hydrogen production but also utilizes it for photothermal synergistic catalysis.