Porous Carbon Aerogel Decorated with TiO₂ Quantum Dots for Highly Improved Photocatalytic H₂ Evolution

Thedesign of photocatalysts plays a central role in determiningthe photocatalytic H-2 yield. Here, we used a design strategythat is different from conventional methods to prepare our photocatalyticsystems. Large porous carbon aerogels (CA) with rich surface areaswere used to receive photogenerated electrons. TiO2 quantumdots were used as photocatalysts and anchored on large porous CAsto form CA@TiO2 systems. The H-2 yield of theoptimized CA@TiO2 composite is & SIM;2.1 mmol/g, & SIM;11times higher than that of pure TiO2 quantum dots. High-resolutionX-ray photoelectron spectroscopy and high-angle annular dark-fieldscanning transmission electron microscopy demonstrate that the photogeneratedelectrons can be easily transferred from TiO2 quantum dotsto porous CAs. Thus, efficient charge separation can be realized forthe succeeding highly efficient H-2 evolution. Our resultshere provide a different way from conventional methods to design photocatalyticsystems with high H-2 yield.