Direct current deposited NiO on polyaniline@MoS2 flexible thin film for highly efficient solar light mineralization of 2-chlorophenol: A mechanistic analysis

Abstract

BackgroundEasily separable and recyclable photocatalysts are highly desirable as they solve the problem of catalyst loss during its separation or reuse in wastewater treatment. Therefore, designing newer multifunctional semiconducting thin films using advanced physical deposition technique and chemical methodologies could be an effective way to fabricate an efficient, recyclable photocatalyst. MethodReusable and flexible NiO-MoS2@polyaniline (NiO-MoS2@Pani) conducting photocatalyst substrate was fabricated by chemical methodology to develop MoS2@Pani and later subjecting it to Direct Current (DC) sputtering to deposit NiO on it. The morphological analysis showed embedded MoS2 in Pani along with the surface covering by NiO. The XRD showed the amorphous nature of the composite, while the XPS confirmed the presence and coating of NiO over MoS2@Pani. Significant findingsA synergistic effect of Pani, MoS2 and NiO in NiO@Pani-MoS2 exhibited 90% degradation of 2-chlorophenol (2-CP) under solar light irradiation. The high catalytic efficiency is ascribed to the increased separation of charge carriers and bandgap engineering due to the constituents' synergistic/additional effect. The formation of heterojunctions between NiO, Pani, and MoS2, i.e., MoS2│Pani, NiO│Pani, NiO│MoS2, and ternary heterojunction like NiO│MoS2│Pani and NiO│Pani│MoS2 are mainly responsible for the better decomposition of 2-CP. After five-time reuse, the NiO@Pani-MoS2 showed promising efficacy and stable morphology, confirming that NiO@Pani-MoS2 thin film is an efficient, easily separable, reusable, and stable photocatalyst.