Enhanced photocatalytic reduction of mercuric cations endorsing fabricated mesoporous BiFeO3/g-C3N4 heterojunction under Vis light irradiation

Abstract

In this probe, enhanced photocatalytic reduction of mercuric cations has been achieved endorsing a novel mesoporous BiFeO3/g-C3N4 heterojunction accommodating various percentages of BiFeO3 nanoparticles (NPs) under Vis light irradiation. Formic acid was adopted as holes sacrificial correlated with pure g-C3N4 nanosheet or BiFeO3 nanoparticles. BiFeO3 NPs of particle dimension of 4–6 nm were homogeneously spread over the surface of the g-C3N4 nanosheet. The superior photocatalytic reduction of mercuric cations endorsing BiFeO3/g-C3N4 heterojunction has been affirmed since enlarging the dopant content (BiFeO3 NPs) from 1 up to 4% brings about an enhancement in the efficacy of the photocatalytic reduction of mercuric cations(Hg) from 38 up to 88% after 1 h of illumination. Obviously, the rate of the photocatalytic removal of mercuric cations endorsing mesoporous BiFeO3/g-C3N4 heterojunction accommodating 4% BiFeO3 NPs was found to be 5.3 and 7.9 times larger when correlated to those of neat BiFeO3 NPs and g-C3N4 nanosheet, accordingly. The superior photocatalytic reduction of mercuric cations under Vis light irradiation via adopting the synthesized BiFeO3/g-C3N4 heterojunction could be appropriated to the very finite particle sizes of BiFeO3 NPs in addition to their excellent dispersion over the g-C3N4 nanosheet surface. Besides, the extensive area, little band gap, and the excellent crystallinity of the synthesized photocatalyst are considered crucial aspects in the photocatalytic achievement of the synthesized BiFeO3/g-C3N4 heterojunction. Interestingly, the stability of the synthesized BiFeO3/g-C3N4 heterojunction towards the photocatalytic reduction of mercuric cations has been affirmed via recycling the photocatalyst up to five runs without pronounced loss in the photocatalytic performance towards mercuric cations reduction. In conclusion, the attained data brings about establishing a novel photocatalyst of Z-scheme type that could be successfully applied for photocatalytic remediation of toxic contaminants under Vis light irradiation.