Uniform sono-dispersed co-catalysts unlock superior CO₂ photoreduction on Bi₂MoO₆/TiO₂

This study investigates the photocatalytic reduction of CO 2 using water vapor in a top-irradiation batch reactor, with M-Bi 2 MoO 6 /TiO 2 serving as the photocatalyst. Various M-Bi 2 MoO 6 /TiO 2 samples with different co-catalysts (M: Ni, Ce, Co, Mo, Cu) were fabricated through a deposition-ultrasound-assisted approach. The prepared samples underwent examination using UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), X-ray diffraction (XRD), Field-emission scanning electron microscopy (FESEM), N 2 adsorption-desorption isotherms, Photoluminescence (PL) and Raman spectroscopy. Methane was identified as the predominant reaction product, and the introduction of co-catalysts through sono-deposition significantly improved the photocatalytic efficiency. The catalysts with various co-catalysts showed different performances in CO 2 reduction. Additionally, the optical properties of the composite samples changed with the deposition of different co-catalysts on the BT support. Compared to pristine TiO 2 , the co-catalyst-loaded composites exhibited superior CO 2 reduction performance. Among them, the Ni-BT sample had the highest methane yield, attributed to the even distribution of Ni nanoparticles, better visible-light absorption, and more effective charge separation and transfer. • Ultrasound dispersion of Ni, Mo, Cu, Co, Ce on Bi2MoO6/TiO2 composite. • Cocatalyst-modified Bi2MoO6/TiO2 enhanced CO2 photoreduction activity. • Ultrasound deposition gave uniform cocatalyst dispersion on the support. • Cocatalyst loading improved optical properties and charge separation. • Ni-BT composite showed the highest methane yield among prepared samples.