Photoconversion of Carbon Dioxide to Methanol Using Doped-Carbon Quantum Dots/TiO<sub>2</sub>

Continuous emissions of carbon dioxide (CO2) into the atmosphere brought several environmental problems. Photoconversion of CO2 not only can produce value-added products (i.e. methanol) but also aim to reduce the environmental problems caused by CO2. The present work demonstrates the preparation of N-Bi co-doped carbon quantum dots/titanium dioxide (N-Bi co-doped CQDs/TiO2) as a visible-light driven photocatalyst for the photoconversion of CO2 to methanol. Hydrothermal-synthesized N-Bi co-doped CQDs were incorporated into TiO2 nanoparticles through facile mixing method. The loading of CQDs in TiO2 matrix resulted in a decrease of band gap to 2.75 and 2.65 eV for N-CQDs and N-Bi CQDs, respectively. Gas chromatography equipped with flame-ionization detection (GC-FID) analysis showed a methanol yield of 17 µmol/gcat from the photoconversion experiment using N-Bi-CQDs/TiO2 photocatalyst composite. The performance of composite was assigned to the loading of N-Bi co-doped CQDs, which reduced the electron-hole recombination in TiO2. Doping of N-Bi played an important role in localizing the photogenerated electron-holes, essentially enhancing the electron transfer at the CQDs/TiO2 interface. Thus, our work could provide insight into the application of CQDs-based photocatalysts in the visible-light driven photocatalytic conversion of CO2 to value-added products.

UTP CRIS Expert