Photodegradation of methyl orange dye over ZnO/CdS PHOTOCATALYST under very low uvc light

Methyl orange (MO) dye has been used widely in various industries. The fact that one of the most water contaminant dominants by MO residue due to the expansion of textile, paper and food colouring used in daily consumption. The variant colours produced from the MO that brought the issue of the water pollutant become concerning as more industries usage in produce more appealing product. Thus, advanced oxidation processes (AOPs) are a method that degrades organic pollutants like MO by converting it into harmless species with the heterogeneous semiconductor oxide as photocatalyst. The absorption edge of the CdS is 516 nm, that allow the visible light to be absorb since the narrower bandgap width with (2.4eV) compared to the other photocatalysts that have broader bandgap (Ebg>3.0eV) that only can absorb the ultraviolet light. Hence, CdS’s narrow band gap (2.4 eV) can be used to adjust the ZnO band gap of (3.37 eV) as CdS help the ZnO absorbs the visible light better consequently, overcome the electron-hole recombination issue. The light-yellow sample of ZnO/CdS obtained by the mixture of ZnO and (Cd(NO₃)₂·4H₂O) with the thiourea solution added ensure that all cadmium ions react with thiourea to form CdS, and the CdS is deposited on ZnO.. Therefore, the stabilisation of doped ZnO photocatalysts with CdS given that the combination of CdS and ZnO can increase the range of solar light absorption, encourage the separation of photogenerated carriers, and accelerate surface reaction kinetics. Subsequently, the surface morphology and composition of ZnO/CdS composites will be examined by the application Fourier transform infrared (FT-IR) spectra in will be used to identify the photocatalyst's functional groups using a FT-IR spectrometer. The implementation of ZnO/CdS composite photocatalyst the greater visible light efficiency will in photodegraded the methyl orange dye in aqueous solution. As a potentially promising material for methyl orange dye pollutant that contaminant in wastewater that can be overcome in water treatment applications, the ZnO/CdS photocatalyst is expected to effectively trap the methyl orange dye under the low UV light.