Biomass-derived N, P-codoped templated biocarbon@2D-MoS2/polypyrrole based hybrids for U(VI) electrosorption

Abstract

In this study, hierarchical mesoporous and N/P-codoped templated biocarbon was prepared from Bambusa vulgaris culms through pyrolysis under reducing conditions. The biocarbon was functionalized with 2D-MoS2 nanosheets via hydrothermal reaction and later different mol fractions of polypyrrole (PPy) were electrodeposited to boost the electrode conductivity. The resultant BBC/PPy composites were characterized comprehensively using XRD, FTIR, SEM-EDX and BET. BBC/PPy-3 deposited with PPy-3 (using 0.3 M pyrrole) exhibited superior electro-sorption performance due its enhanced specific resistance, Csp (140.4 F/g) and high specific surface area, Asp (128.77 m2/g). The heteroatoms doping into biocarbon brought the essential chelating capability and hydrophilicity. BBC/PPy-3 showed remarkable sorption capacity of 402.5 mg/g at optimized value of pH (4.5–5.0). The electrochemical impedance spectroscopic (EIS) data revealed that BBC/PPy-3 presented relatively small charge transfer resistance Rct (1.78 Ω cm2), minute electrolytic resistance, Rs (0.97 Ω cm2) and large double layer constant phase element, qdl (0.0357 S sn/ cm2). The galvanostatic charge discharge (GCD) curves showed all composites as stable supercapacitors. BBC/PPy composites proved themselves as competitive and selective materials for the economic removal of U(VI) from effluents containing low concentration of U(VI).