Constructing C-doped TiO2/β-Bi2O3 hybrids Z-scheme heterojunction for enhanced CO2 photoreduction

Rational fabricating advanced photocatalysts to recycle CO 2 into solar fuel is one of the most promising approaches to simultaneously address energy shortages and global warming. TiO 2 has been widely used in photocatalytic CO 2 reduction due to its abundant reserves, non-toxicity and harmlessness etc. However, it remains significantly challenging for practical applications due to the fast electron-hole recombination. Herein, we design a direct TiO 2 based Z-Scheme heterojunction by self-assembly of C-doped TiO 2 nanoparticles on 3D hierarchical petal of flower-like β-Bi 2 O 3 (C-TiO 2 /β-Bi 2 O 3 ). In situ electron paramagnetic resonance tests, in situ X-ray photoelectron spectroscopy and theoretical calculations reveal that electrons are transferred from β-Bi 2 O 3 to C-TiO 2 due to the formation of Z-Scheme heterojunction, which greatly accelerates the separation of photogenerated carriers to promote efficient CO 2 photoreduction. Ultimately, the optimal heterojunction shows significantly enhanced photocatalytic activity for CO 2 reduction to CO (31.07 μmol g –1 h −1 ) compared to the pure TiO 2 (3.28 μmol g –1 h −1 ) without using any photosensitizers and sacrificial agents. This work provides a unique insight to design direct Z-Scheme heterojunctions and delivers a promising photocatalyst for overcoming global warming and energy-supply issues.