Wei Li,Hao Ding,Hua Ji,Wenbin Dai,Jianping Guo,Gaoxiang Du
A photocatalytic active CdS-TiO2heterostructure composite was prepared by hydrothermal method and its morphology and properties were characterized. Results indicate that the CdS nanoparticles deposited on the surface of a TiO2nanoparticles, which was in anatase phase. The particle scale of both of the components reached approximately 15 nm. In comparison to pure TiO2(410 nm), the light absorption edge of the heterostructure composite was 550 nm, which could extend the light response from UV to the visible region. Under visible light irradiation, the degradation efficiency of tetracycline hydrochloride by the CdS-TiO2composite achieved 87.06%, significantly enhancing photocatalytic activity than the as-prepared pure TiO2and commercial TiO2(Degussa P25). This character is attributed to the synergetic effect of these two components in the absorption of visible light.Keywords:CdS-TiO2heterostructure composite;photocatalyst;tetracycline hydrochloride
Fengyu Tian,Dongfang Hou,Fuchao Hu,Kui Xie,Xiuqing Qiao,Dongsheng Li
1D porous CdS nanoparticles/TiO 2 nanofibers heterostructure has been fabricated via simple electrospinning and a successive ionic layer adsorption and reaction (SILAR) process. The morphology, composition, and optical properties of the resulting CdS/TiO 2 heterostructures can be rationally tailored through changing the SILAR cycles. The photocatalytic hydrogen evolution and decomposition of rhodamine B (RhB) of the as-synthesized heterostructured photocatalysts were investigated under visible light irradiation. Compared to TiO 2 nanofibers,the as-obtained CdS/TiO 2 heterostructures exhibit enhanced photocatalytic activity for hydrogen production and decomposition of RhB under visible-light irradiation. The heterojunction system performs best with H 2 generation rates of 678.61 μmol h −1 g −1 under visible light irradiation which benefits from the two effects: (a) the 1D porous nanofibrous morphology contributes to not only more active sites but also more efficient transfer of the photogenerated charges (b) the synergetic effect of heterojunction and photosensitization reducing the recombination of photogenerated electrons and holes.
Photocatalytic water splitting for hydrogen production and the degradation of organic pollutants are regarded as promising strategies to address the current energy crisis and environmental issues. As a wide-bandgap metal oxide, TiO 2 is characterized by low catalytic activity and a narrow range of light absorption when used alone, whereas its combination with narrow-bandgap semiconductors has been shown to lead to a significant enhancement in catalytic performance. In this study, CdS–TiO 2 composites were synthesized via a ball-milling method, after which Pt–Pd nanoparticles were deposited by photodeposition. The noble metals were found to interact with CdS and TiO 2 respectively, while a synergistic catalytic effect between Pd and Pt was also observed. The photocatalytic efficiency was further extended by the formation of CdS–TiO 2 heterojunctions, resulting in a significantly enhanced hydrogen production rate of 4656.99 μmol h −1 g cat −1 in the ternary system. Moreover, the composite demonstrated significantly enhanced performance in the photocatalytic reduction of 4-NP, The Pt–Pd NPs/CdS-Vo-TiO 2 photocatalyst achieved a 95.2 % conversion rate for 4-NP within 2 min, also demonstrating high photocatalytic activity.