Hierarchical hyper-branched titania nanorods with tuneable selectivity for CO photoreduction.

Utilising captured CO and converting it into solar fuels can be extremely beneficial in reducing the constantly rising CO concentration in the atmosphere while simultaneously addressing energy crisis issues. Hence, many researchers have focused their work on the CO photoreduction reaction for the last 4 decades. Herein, the titania hyper-branched nanorod (HBN) thin films, with a novel hierarchical dendritic morphology, revealed enhanced CO photoreduction performance. The HBNs exhibited enhanced photogenerated charge production (66%), in comparison with P25 (39%), due to the unique hyper-branched morphology. Furthermore, the proposed HBN thin films exhibited a high degree of control over the product selectivity, by undergoing a facile phase-altering treatment. The selectivity was shifted from 91% towards CO, to 67% towards CH. Additionally, the HBN samples showed the potential to surpass the conversion rates of the benchmark P25 TiO in both CO and CH production. To further enhance the selectivity and overall performance of the HBNs, RuO was incorporated into the synthesis, which enhanced the CH selectivity from 67% to 74%; whereas the incorporation of CuO revealed a selectivity profile comparative to P25.