In the present study, carbon cloth (CC) was functionalized using dimethyl sulfoxide (DMSO) and employed as an excellent bioanode for improving defluoridation efficiency, wastewater treatment and power output from a microbial desalination cell (MDC). The Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis of DMSO modified carbon cloth (CCDMSO) confirmed the functionalization of CCDMSO and the water drop contact angle of 0° ensured its superior hydrophilicity. The presence of –COOH (carboxyl), S[dbnd]O (sulfoxide) and O–C[dbnd]O (carbonyl) functional groups on CCDMSO aids in enhancing the performance of the MDC. Besides, cyclic voltametric and electrochemical impedance analysis revealed that CCDMSO had an excellent electrochemical performance with low charge transfer resistance. Replacing CC with CCDMSO as anode in MDC, the time required for 3,10 and 20 mg/L of initial fluoride (F−) concentrations in the middle chamber was reduced from 24 ± 0.75 to 17 ± 0.37, 72 ± 1 to 48 ± 0.70 and 120 ± 0.5 to 96 ± 0.53 h, respectively to meet the prescribed standards (1.5 mg/L). Furthermore, using CCDMSO, the anode chamber of MDC exhibited a maximum of 83% substrate degradation and simultaneously, the power output is increased by 2–2.8 times. CCDMSO improved the power production from 0.009 ± 0.003, 1.394 ± 0.06 and 1.423 ± 0.15 mW/m2 to 0.020 ± 0.07, 2.748 ± 0.22 and 3.245 ± 0.16 mW/m2, respectively, for initial F− concentrations of 3,10 and 20 mg/L. Modifying CC with DMSO thus proved to be an efficient and simple methodology for enhancing the overall performance of MDC. © 2023 The Authors