Ti3C2 MXene supporting platinum nanoparticles as rapid electrons transfer channel and active sites for boosted photocatalytic water splitting over g-C3N4.

Two-dimension (2D) MXene materials have increasingly attracted attentions in improving the photocatalytic conversion of solar-to-chemical energy over graphitic carbon nitride (g-C3N4). In this work, Pt nanoparticles modified few-layer Ti3C2 MXene sheet (MXene@Pt) was successfully prepared by chemical reduction, which was used as efficient co-catalysts to enhance the photocatalytic hydrogen evolution over porous g-C3N4 (PCN). The high work function of MXene@Pt and the tight 2D/2D interfacial contact between MXene@Pt and PCN significantly promoted the transfer and separation of photogenerated electron-hole. Besides, the MXene@Pt could enhance the light-harvesting of PCN and provide plentiful active sites for hydrogen evolution reaction. The hydrogen evolution activity of optimum 2D/2D MXene@Pt modified PCN (PCN/MPt-5) composite was dramatically enhanced, even higher than that of equal Pt mass modified PCN. Besides, overall water splitting was realized via a two-electron pathway with H2O2 and H2 generation. This work may provide the fabrication strategy for developing MXene-based co-catalyst in photocatalysis.

Bismuth chromate (Cr2Bi3O11): a new bismuth-based semiconductor with excellent photocatalytic activity.

A novel bismuth chromate material (Cr2Bi3O11) was synthesized by a direct mixing method with higher photocatalytic activity in both organic pollutant detoxification and oxygen evolution. Cr2Bi3O11 with a band gap of 2.20 eV could be activated by photons with a wavelength below 561 nm. This work not only provides an approach for the controllable synthesis of Cr2Bi3O11, but also experimentally and theoretically shows its excellence and potential when applied in photocatalysis.

In-situ construction of ternary Ti3C2 MXene@TiO2/ZnIn2S4 composites for highly efficient photocatalytic hydrogen evolution.

Facing the demand of cleaning energy, the development of efficient photocatalysts for hydrogen evolution is a promising way to realize solar-to-chemical energy conversion for solving energy crisis. Hence, a novel hierarchical Ti3C2 MXene@TiO2/ZnIn2S4 photocatalyst with rapid charge transfer channels was constructed by two-step hydrothermal for efficient hydrogen production, adopting hydrothermal oxidation to in-situ synthesize Ti3C2 MXene embedded with TiO2 nanosheets (M@TiO2), which was applied to load ZnIn2S4 (ZIS). The hybridized photocatalyst with optimized ZIS amount had a hydrogen generation rate of 1185.8 µmol/g/h, which was higher than that of M@TiO2 and pure ZIS. That was originated from the outstanding light harvesting of ZIS and Ti3C2, sufficient active sites of Ti3C2, intimate interfacial contact, and efficient separation and transfer of photogenerated charges via heterojunction. The favorable and rapid charge transfer routes included type-II heterojunction between ZIS and TiO2 nanosheets, Schottky junction of Ti3C2/semiconductor, and metallic Ti3C2 with high conductivity. This work revealed the Schottky junction forming between ZIS and Ti3C2, and hierarchical M@TiO2 could be served as advantageous platform and efficient cocatalyst to construct MXene-based photocatalyst.