Hydrothermal in-situ synthesis of MoSe2-polypyrrole nanocomposite for efficient photocatalytic degradation of dyes under dark and visible light irradiation.

• Novel photocatalyst MoSe 2 -PPy was prepared and characterized. • Degradation of cationic and anionic dyes in dark and light conditions. • Explanation on the basis of IPCE, TCSPC, BET, zeta potential and EIS measurement. • Intermediates products were studied using LC-MS. • Reusability experiments were also performed. A novel round the clock (day-night) photocatalyst has been developed based on MoSe 2 and polypyrrole (PPy) using two-step method including hydrothermal and in-situ polymerization process. Synthesized samples were characterized by XRD, FESEM, TEM, FTIR, Raman, UV–Visible and XPS techniques. Visible light-induced photocatalytic and adsorption performance were studied by carrying out the degradation of cationic and anionic dyes. The enhancement in degradation performance was attributed to the promoted absorption of photons in the visible region (as evident through IPCE measurement), improved charge separation (as noticed through TCSPC), high surface area (as evident through BET), optimized surface charge (observed by zeta potential), conductive behavior and slow charge transfer resistance (as noticed by EIS). The intermediate products after photocatalytic degradation of dyes were analyzed using LC-MS studies. Our studies showed that MoSe 2 -PPy nanocomposite has the potential efficiency, reusability and stability which make it an ideal catalyst for dye degradation. [ABSTRACT FROM AUTHOR]