G-C3N4/Ca2Fe2O5 heterostructures for enhanced photocatalytic degradation of organic effluents under sunlight

Durga Sankar Vavilapalli,R K Sharma,Shubra Singh,M S Ramachandra Rao,Raja Gopal Peri,B Muthuraaman,U K Goutam

doi:10.1038/s41598-021-99020-6

Abstract

g-C3N4/Ca2Fe2O5 heterostructures were successfully prepared by incorporating g-C3N4 into Ca2Fe2O5 (CFO). As prepared g-C3N4/CFO heterostructures were initially utilized to photodegrade organic effluent Methylene blue (MB) for optimization of photodegradation performance. 50% g-C3N4 content in CFO composition showed an enhanced photodegradation efficiency (~ 96%) over g-C3N4 (48.15%) and CFO (81.9%) due to mitigation of recombination of photogenerated charge carriers by Type-II heterojunction. The optimized composition of heterostructure was further tested for degradation of Bisphenol-A (BPA) under direct sunlight, exhibiting enhanced photodegradation efficiency of about 63.1% over g-C3N4 (17%) and CFO (45.1%). The photoelectrochemical studies at various potentials with and without light illumination showed significant improvement in photocurrent response for g-C3N4/Ca2Fe2O5 heterostructures (~ 1.9 mA) over CFO (~ 67.4 μA). These studies revealed efficient solar energy harvesting ability of g-C3N4/Ca2Fe2O5 heterostructures to be utilized for organic effluent treatment.

Highlights

G-C3N4/Ca2Fe2O5 heterostructures were successfully prepared by incorporating g-C3N4 into Ca2Fe2O5 (CFO)
With increase in g-C3N4 content in g-C3N4/CFO composite from 10 to 75%, the intensity of diffraction peaks corresponding to g-C3N4 increased gradually without further secondary phase formation
In order to enhance the photocatalytic activity over bare CFO and g-C3N4, g-C3N4/CFO heterostructures were synthesized to reduce the recombination of photogenerated electron–hole pairs and effective charge separation. g-C3N4 has a 2-dimentional graphite like structure constituting of π-conjugated systems, which are responsible for delocalization of electrons throughout the π-network[47]

Summary

Introduction

G-C3N4/Ca2Fe2O5 heterostructures were successfully prepared by incorporating g-C3N4 into Ca2Fe2O5 (CFO). The photocatalytic performance of g-C3N4/CFO heterojunctions were analyzed by degrading organic effluents MB and BPA under natural sunlight. The photocatalytic performance of these heterostructures was investigated during degradation of organic effluent Methylene blue (MB) and polycarbonate plasticizer Bisphenol-A (BPA) under natural sunlight. XPS spectra of Ca 2p of CFO and CCN50 shown in Fig. 3(a&d) constitute of two peaks arising from spin orbit coupling of Ca 2 p3/2 and Ca 2 p1/2.

Results

Conclusion