Undoped and carbon-doped calcium molybdate as photocatalyst for degradation of methylene blue

Department of Chemistry, PAHER University, Udaipur-313 024, Rajasthan, India Department of Chemistry, B. N. University, Udaipur-313 002, Rajasthan, India Department of Chemistry, J. R. N. Rajasthan Vidhyapeeth (Deemed to be University), Udaipur-313 002, Rajasthan, India E-mail: hardeepshre@gmail.com Manuscript received online 20 October 2020, revised and accepted 28 November 2020 Calcium molybdates (undoped and carbon-doped) were synthesized and used as photocatalysts for the degradation of meth­ylene blue. These photocatalysts have been characterized by different techniques such as FE-SEM, EDX and XRD. The progress of the photocatalytic degradation was observed spectrophotometrically. The effect of different parameters such as pH, concentration of dye, amount of semiconductor and light intensity on the rate of degradation of methylene blue was ob­served. Optimum values were obtained as pH = 8.5, concentration of methylene blue = 1.10×10–4 M, amount of CaMoO4 = 0.10 g and light intensity = 50.0 mW cm–2. A tentative mechanism for the photocatalytic degradation of methylene blue has been proposed. Scavenger studies indicated that hydroxyl radical is acting as an oxidizing species for this degradation. It was observed that 2% C-doped showed almost 1.4 times better photocatalytic performance than undoped CaMoO4 sample. &nbsp