In-situ producing CsPbBr3 nanocrystals on (001)-faceted TiO2 nanosheets as S­scheme heterostructure for bifunctional photocatalysis.

Fabricating a cost-effective yet highly active photocatalyst to reduce CO2 to CO and oxidize benzyl alcohol to benzaldehyde simultaneously, is challenging. Herein, we construct an S-scheme 0D/2D CsPbBr3/TiO2 heterostructure for bifunctional photocatalysis. An in-situ synthetic route is used, which enables the precise integration between CsPbBr3 nanocrystals and ultrathin TiO2 nanosheets exposed with (001) facets (termed as TiO2-001), resulting in a tightly coupled heterointerface and desirable band offsets. The as-prepared CsPbBr3/TiO2-001heterojunctions exhibit boosted charge carrier kinetics, particularly, quick carrier separation/transfer and efficient utilization. Experimental results and theoretical calculations validate the S-scheme route in CsPbBr3/TiO2-001, which allows the enrichment of strongly conserved electrons-holes at conduction and valence bands of CsPbBr3 and TiO2-001, respectively. Consequently, compared to its counterparts, an excellent bifunctional activity (with 24 h reusability) is realized over CsPbBr3/TiO2-001, where the production rate of CO and benzaldehyde reach up to 78.06 µmol g-1h-1 and 1.77 mmol g-1h-1 respectively, without employing any sacrificial agents. This work highlights the development of perovskite-based heterostructures and describes the efficient harnessing of redox potentials and charge carriers towards combined photocatalytic systems.

Poly(sodium 4-styrenesulfonate) Assisted Room-Temperature Synthesis for the Mass Production of Bismuth Oxychloride Ultrathin Nanoplates with Enhanced Photocatalytic Activity.

Bismuth oxychloride ultrathin nanoplates (BiOCl-UTNs) are highly active, but their preparation are limited to closed-vessel hydrothermal and solvothermal techniques at high temperatures (110-180 °C). Here we report a straightforward poly(sodium 4-styrenesulfonate) (PSS)-mediated route for the large-scale synthesis of BiOCl-UTNs at room-temperature. In an open vessel, 6.15 g of BiOCl-UTNs with 3-5 nm thickness, and planar dimensions of 30-50 nm were produced. The strong electrostatic interaction between PSS and [Bi2 O2 ]2+ layers inhibited the growth rate of BiOCl nanoplates along <001> direction, and Na+ ions governed the electrolyte sedimentation to produce BiOCl-UTNs. The resulting BiOCl-UTNs exhibited high photocatalytic activity for the degradation of antibiotics and organic dyes because of their large specific surface area, increased light absorption ability, and fast separation and transfer efficiency of the photoexcited charge carriers.