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

Abstract

The design of photocatalysts plays a central role in determining the photocatalytic H 2 yield. Here, we used a design strategy that is different from conventional methods to prepare our photocatalytic systems. Large porous carbon aerogels (CA) with rich surface areas were used to receive photogenerated electrons. TiO 2 quantum dots were used as photocatalysts and anchored on large porous CAs to form CA@TiO 2 systems. The H 2 yield of the optimized CA@TiO 2 composite is ∼2.1 mmol/g, ∼11 times higher than that of pure TiO 2 quantum dots. High-resolution X-ray photoelectron spectroscopy and high-angle annular dark-field scanning transmission electron microscopy demonstrate that the photogenerated electrons can be easily transferred from TiO 2 quantum dots to porous CAs. Thus, efficient charge separation can be realized for the succeeding highly efficient H 2 evolution. Our results here provide a different way from conventional methods to design photocatalytic systems with high H 2 yield.

Phase Transformation Strategies for the Construction of Heterojunction TiO2 Photocatalysts

“…In recent years, the development of renewable green clean energy-hydrogen is considered to play an important role in solving the increasing energy shortage and environmental pollution problems. [1][2][3] Photocatalytic hydrogen production has been widely applied as a clean and efficient technology, which can realize the conversion of solar energy with lowdensity to chemical energy with high-density. [4] In order to improve the absorption of visible light and the separation efficiency of photogenerated carriers in the process of photocatalytic, the research of efficient photocatalysts is of great significance.…”

In Situ Growth of Ultrathin CdS Nanosheets on Porous Carbon Aerogels for Improved Photocatalytic H2 Production

“…Solar energy is a clean source that can produce hydrogen energy from water splitting. − Because solar energy originates from the light irradiation of sunlight, no extra consumption is needed for producing hydrogen energy. Accordingly, the hydrogen energy from photocatalytic reactions has been one of the important fields. , For photocatalytic reactions, a photocatalyst is needed. − The photocatalyst is excited by light irradiation. Separated electrons and holes in the photocatalyst are generated for the succeeding photocatalytic H 2 evolution. − Therefore, the design of photocatalysts is very important for the excitation and separation of electrons and holes. − …”