Cu-α-NiMoO4 photocatalyst for degradation of Methylene blue with pathways and antibacterial performance

- Fabrication of Cu-α-NiMoO4 rods by microwave hydrothermal method.
- Photocatalytic enhancement by copper doping in α-NiMoO4 in solar light.
- Identification of degradation products of Methylene blue by HR-QTOF ESI/MS.
- Propose a degradation pathway of Methylene blue.
- Strong tendency to inactivate S. aureus, B. Subtilis, and P. aeruginosa.

Cu doped α-NiMoO4 photocatalyst has been synthesized by microwave hydrothermal method. The existence of Cu2+ ions at lattice position of α-NiMoO4 was observed on the basis of XRD, HRTEM, SAED, and EDS analysis. The negative zeta potential values indicate the stability of samples. Solar light driven photocatalytic degradation of Methylene blue (MB) dye in water was used to evaluate the photocatalytic performance of Cu doped α-NiMoO4 photocatalyst. The results revealed that there is an optimum Cu (4 mol%) doping level leads to highly enhanced photocatalytic activity of Cu-α-NiMoO4, as compared to α-NiMoO4 host. The experiment also suggested that active species (OH, O2− and h+) play a crucial role in the scavenging system. The reduced energy band gap, oxygen vacancy, high BET surface area, and efficient separation of photogenerated electron/hole are responsible for enhancement of photocatalytic performance. MB photodegradation intermediates were identified by high resolution-quadruple time of flight electrospray ionization mass spectrometry (HR-QTOF ESI/MS) in positive ion mode and degradation pathway was proposed. Antibacterial performance was analyzed against Gram-positive (methicillin resistant Staphylococcus aureus and Bacillus Subtilis) and Gram-negative bacteria (Pseudomonas aeruginosa) via well-diffusion method. The formation of larger inhibition zone by small quantity of photocatalyst powder proved the excellent antibacterial performance. The inactivation of microorganism were found in following order: B.Subtilis ˃ S.aureus ˃ P.aeruginosa. The result of our study suggested that copper doped α-NiMoO4 photocatalyst is suitable for degradation of organic contaminates as well as effective for growth inhibition of multidrug-resistant microorganisms.

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