Green preparation of Carbon Quantum dots using Gingko biloba to sensitize TiO2 for the photohydrogen production

Carbon Quantum dots (CQDs) were obtained from Gingko biloba by using microwave technique, which is easy, time-saving, cost-effective, non-toxic and environmental friendly way. TiO2 were sensitized by green-prepared CQDs to obtain CQDs/TiO2 composite. The characterizations of the CQDs and CQDs/TiO2 were performed by Transmission Electron Microscopy (TEM), high-resolution TEM (HR-TEM), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopic (XPS), Photoluminescence (PL) and Fourier Transformed Infrared (FT-IR) spectroscopy. The photocatalytic hydrogen evolution activity of CQDs/TiO2 system was studied under visible light (lambda > 420 nm) irradiation in the aqueous solution by using triethanolamine (TEOA) as a sacrificial electron donor. When Pt was used as a co-catalyst, CQDs/TiO2/Pt exhibited improved hydrogen evolution rate (1502 mu mol h(-1)g(-1)) compared to CQDs/TiO2 composite (665 mu mol h(-1)g(-1)).