Simultaneous green synthesis of H₂ and decolorization of distillery effluent by photocatalysis via gold-decorated TiO₂ photocatalysts

In this work, the green H₂ production and decolorization of industrial distillery effluent were carried out by the photocatalytic process via a gold-decorated TiO₂ photocatalyst synthesized by the photodeposition. Effects of dilution (0–150 folds), decorated gold content on TiO₂ (0.1–0.7 wt%), ethanol concentration (0–20 vol%) and photocatalyst loading (2–5 g/L) on the photocatalytic activity were explored. The preliminary results illustrated that neither H₂ production nor decolorization were achieved via the fresh distillery effluent. The maximum H₂ production of 210 μmol/g with 64.4 % decolorization was achieved with the 100-fold diluted-distillery effluent using the 0.3 wt% gold decorated on TiO₂ (Au_0.3T) photocatalyst at loading of 3 g/L and ethanol concentration of 15 vol%. The characterization and experiment results pointed out that the improved photocatalytic activity of Au_0.3T photocatalyst was based on the available area of decorated gold nanoparticles (NPs), the Au–TiO₂ interface area and interface perimeters. Via the distillery effluent, the water splitting was the dominate reaction for H₂ production, accounting of around 93% of overall produced H₂. Although a low recycling stability was observed from this work, attributing to the accumulation of organic contaminants founded in the distillery effluent on the surface of the photocatalyst, this finding may pave the way for the design of metal-decorated semiconductors for simultaneous green H₂ production and pollutant removal from actual industrial wastewater.