Improved charge separation and surface activation via boron-doped layered polyhedron SrTiO3 for co-catalyst free photocatalytic CO2 conversion

For efficient photocatalytic CO2 conversion to solar fuel, it is highly desired to enhance the solar-light absorption, photogenerated charge separation and surface active/catalytic performance of semiconductor photocatalysts. Herein, we have successfully prepared boron-doped layered polyhedron SrTiO3 (STO) by solid-state method using specific TiB2 precursor as boron and titanium resource. The prepared polyhedron STO is single-crystal structure with average diameter of ∼500 nm and boron-doped STO exhibits overlapped-layer structure. The boron doping amount could be controlled using TiB2. It is shown that the amount optimized boron-doped layered polyhedron STO sample Exhibit 3-times enhanced co-catalyst free photocatalytic activity for CO2 conversion, compared to the bare STO nanoparticles. Notably, the improved photocatalytic performance could be attributed to the enhanced charge separation as confirmed by means of fluorescence emission spectra related to produced [rad]OH radicals, surface photovoltage responses and photoelectrochemical measurements; and the enhanced CO2 surface adsorption and catalytic performance of boron-doped SrTiO3 as verified by CO2-TPD and electrochemical CO2 reduction experiments. This work implies that boron-doped layered polyhedron SrTiO3 would display promising applications in the photocatalytic field of CO2 conversion to solar fuels.