Facile Synthesis of Pd loaded g-C3N4/TiO2 heterojunction catalyst with enhanced photothermal catalytic performance in Suzuki Coupling under moderate condition

Photothermal synergistic catalysis of Suzuki-Miyaura coupling reaction not only utilizes the solar energy efficiently, but also reduces the energy consumption. It is a green organic synthesis method for constructing C–C bonds, which has a wide application. In this work, we constructed a PdO/g-C3N4/TiO2 bilayer tubular structure material with a heterojunction structure by a simple and effective method. The catalyst exhibited efficient photothermal synergistic catalytic performance in Suzuki coupling reaction under visible light irradiation. The influence of the catalyst’s structure, morphology, composition, and photothermal response on the Suzuki coupling reaction were discussed based on a series of characterizations and activity test of the catalyst. The results showed that the PdO/g-C3N4/TiO2 catalyst contained an effective g-C3N4/TiO2 heterojunction structure. Under visible illumination, the differences in interfacial charge concentration and electron affinity between these two different types of semiconductors lead to charge rearrangement and transfer, which greatly improves the carrier separation efficiency. Meanwhile, palladium metal exhibits excellent electron deposition effects, both as an active metal center for SMC reactions and as an electron acceptor for facilitating photoelectron transfer. Electron-rich palladium atoms play an important role in C–C bond formation reactions, improving catalytic efficiency. The PdO/g-C3N4/TiO2 catalyst has excellent catalytic activity and can catalyze the SMC reaction under visible light and at 0 ℃, the yield reached 85.6%, which is comparable to the activity of thermal catalysis for 15minutes. Furthermore, after five cycles, the PdO/g-C3N4/TiO2 catalyst still maintained an 83.1% yield, demonstrating excellent cycle stability. This article offers an effective strategy for preparing heterojunction catalyst with visible light response for photothermal reaction and presents the potential of these catalysts as a way to improve the efficiency and sustainability of Suzuki coupling reactions.