Abstract
Synthesis and characterization of dual functioning material is an effective approach for promotion of organic pollutant degradation through adsorption as well as photocatalysis. Herein, graphene oxide modified by addition of barium nitrate and iron to construct smooth sheet-like structure (BaFe2O4/rGO) for removal of Chlorhexidine Digluconate (CHD). Compare with GO (75.69% -UV-light ;88.17%-visible-light), BaFe2O4/rGO showed significant adsorption-photocatalysis effect under visible-light (93.95%) than UV-light (78.17%). The introduction of barium nitrate and iron into graphene oxide led to smooth porous structure with increased surface area (93.66 m2 g-1), which resulted in large number of adsorption active site and great photocatalytic activity with efficient charge separation. Although, catalysts did not mineralize CHD completely, but the parent compound mineralized to some extent, which was confirmed by the TOC measurement and UV254 absorbance variation. In addition, toxicity of degraded products was analyzed by bacterial susceptibility test on Bacillus cereus DPAML065 suggested that nontoxic byproducts of CHD formed, which led to their safe disposal. Based on the identified transformed products, the possible degradation pathway was proposed. Batch studies demonstrated that BaFe2O4/rGO is highly photoactive based on reaction rate constant (R2=0.984), where the kinetics data was well-fitted using the pseudo-first order. Moreover, efficiency of catalysts was examined under solar light to achieve the sustainability.
Solar Light-Driven Photocatalysis Using BaFe2O4/rGO for Chlorhexidine Digluconate Contaminated Water: Comparison With Artificial UV and Visible Light-Mediated Photocatalysis