Green synthesis of a copper–titanium oxide photocatalyst via liquid-assisted resonant acoustic mixing for hydrogen generation

Conventional methods for synthesizing catalytic materials usually involve utilizing large volumes of solvents, auxiliary substances, and additives to give the desired properties and reactivity to the final products. Consequently, these routes imply the production of waste with potential negative impacts on the environment and living organisms. This work explored a simple, liquid-assisted resonant acoustic mixing (RAM) process to produce copper oxide (CuO x )-modified titanium dioxide (TiO 2 ) heterostructures that are active in the photocatalytic production of hydrogen (H 2 ) from water. The synthesis involves a mixture of precursors and a neglectable amount of water, resulting in eliminating unnecessary work-up stages. RAM acceleration and water content were adjusted to achieve the most homogenous catalysts that show a significant enhancement in photocatalytic hydrogen generation compared to pristine TiO 2 . These promising results open the possibility to further explore RAM-based methods as greener synthesis routes for the obtention of a wider diversity of materials. • CuO x /P25 heterostructured photocatalysts were synthesized using RAM with a negligible amount of solvents involved. • CuO x /P25 showed uniform dispersion of the Cu species on the TiO 2 surface. • The presence of Cu 1+ enhances the photocatalytic H 2 evolution performance.