Microwave-assisted synthesis of NiTe2 photocatalyst as a facile and scalable approach for energy-efficient photocatalysis and detoxification of harmful organic dyes

Abstract

Microwave-assisted synthesis of NiTe2, a metal dichalcogenide, is reported here as a facile and rapid preparation method for energy-efficient and scalable photocatalysis application and detoxification of water pollution. Synthetic dyes as organic pollutants in water, such as Methylene blue, Congo red, and Methyl orange cause serious health and environmental issues, which are degraded effectively by heterogeneous photocatalysis using NiTe2 as a catalyst. The photons from a UV-source generates excitons within the surface of NiTe2 that can react with O2, H2O, and hydrogen peroxide (H2O2) initiator to convert them into reactive superoxide anions (−O2), hydroperoxyl (HOO), and hydroxide radicals (OH) which holds strong oxidizing power to degrade organic dye molecules. The UV irradiation can also perform photolysis in the presence of a hydrogen peroxide initiator within the catalyst system. The 3D-support structure of nickel foam substrate and needlelike rod structure of NiTe2 catalyst provides a high surface area. This 3D solid structure can solve the major issue of catalyst separation after treatment which is a major problem in powder catalysts. Our study demonstrates excellent photocatalytic dye-degradation efficiency within a very short treatment time, can replace other Fenton-based catalysts that produce a large amount of iron sludge, and are difficult to remove.