Composite photocatalyst and preparation method thereof

Abstract

The invention discloses a composite photocatalyst and a preparation method thereof, and belongs to the field of photocatalysis. The composite photocatalyst comprises a MoS2 nanosheet and an II type CdSe / CdTe quantum well adsorbed to the MoS2 nanosheet, wherein the II type CdSe / CdTe quantum well comprises a CdSe quantum chip nuclear layer and a CdTe quantum chip shell layer. The composite photocatalyst has the advantages of high light absorption efficiency, high separation efficiency of interfacial charge, weak recombination action of the interfacial charge, high quantum yield of photocatalytichydrogen production and the like. The preparation method of the composite photocatalyst comprises the following steps: dropwise adding first reaction liquid containing the MoS2 nanosheet into secondreaction liquid containing the II type CdSe / CdTe quantum well and carrying out ultrasonic dispersion to obtain the composite photocatalyst. The preparation method has the advantages of good controllability, low cost and wide application range; the prepared photocatalyst has high light absorption efficiency and high hydrogen production efficiency.

Description

technical field [0001] The invention relates to the field of photocatalysis, in particular to a composite photocatalyst and a preparation method thereof. Background technique [0002] Solar photocatalytic hydrogen production, as a "dream technology in the 21st century", is considered to be one of the ultimate solutions to energy and environmental problems. Since Fujishima and Honda first reported the phenomenon of photocatalytic hydrogen production in 1972, researchers have conducted a lot of research on photocatalysts and made a series of breakthroughs and progress. [0003] Semiconductors commonly used in photocatalysts are TiO 2 、C 3 N 4 , NiS, etc., and compared with such traditional semiconductors: the spectrum and energy level of quantum-confined low-dimensional nanocrystals (quantum materials such as quantum dots, quantum rods, and quantum sheets) can be adjusted with their size, and due to their The quantum confinement effect, whose wave function is strongly exte...

AI Technical Summary

Problems solved by technology

[0004] However, the existing technology has the following problems: first, the light absorption cross-section of zero-dimensional quantum dots or one-dimensional quantum rods is limited, and the light absorption efficiency of the catalyst needs to be improved; second, the electronic structure of the previously used quantum dots / rods has not been Due to the special design, the electron population is irregular, which leads to: on the one hand, the speed of electron transfer from the quantum dot / rod to the co-catalyst is limited, and it is difficult to achieve efficient separation of the interface charges between the two; on the other hand, the separated electrons are transferred to the quantum The recombination process of dots / rods cannot be effectively controlled, and the lifetime of separated electrons is affected by the recombination process, which makes it difficult to meet the long-distance diffusion requirements of electrons in cocatalysts

The light absorption cross-sections of the above-mentioned zero-dimensional quantum dots and one-dimensional quantum rods and the defects in the interfacial charge process between the quantum dots / rods and the co-catalyst lead to the limitation of the photocatalytic performance of the composite catalyst.

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