A Comparative Study of the Effect of Graphene Oxide, Graphitic Carbon Nitride, and Their Composite on the Photocatalytic Activity of Cu3SnS4

Abstract

Photocatalysis has shown high potential in dealing with the ever-broadening problem of wastewater treatment, escalated by the increasing level of recalcitrant chemicals often referred to as emerging contaminants. In this study, the effect of support material on the photocatalytic activity of copper tin sulfide (Cu3SnS4) nanoparticles for the degradation of tetracycline as an emerging contaminant is presented. Graphene oxide, protonated graphitic carbon nitride, and a composite of graphitic carbon nitride and graphene oxide were explored as support materials for Cu3SnS4 nanoparticles. The nanoparticles were incorporated with the different carbonaceous substrates to afford graphene-supported Cu3SnS4 (GO-CTS), protonated graphitic carbon nitride-supported Cu3SnS4 (PCN-CTS), and graphene oxide/protonated graphitic carbon nitride-supported Cu3SnS4 (GO/PCN-CTS). Physicochemical, structural, and optical properties of the prepared nanocomposites were characterized using techniques such as Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis near infrared, and fluorescence spectrophotometry. The compositing of the Cu3SnS4 nanoparticles on the support materials was confirmed by the characterization techniques, and the optical properties of the composites were found to be influenced by the nature of the support material. The incorporation of CTS into the support materials resulted in a reduction in band gap energy with evaluated band gaps of 1.65, 1.46, 1.43 eV, and 1.16 eV. The reduction in band gap energy suggests the potential of the composites for enhanced photocatalytic activity. From the photocatalytic study, the degradation efficiency of tetracycline by CTS, PCN-CTS, GO-CTS, and PC/GO-CTS was 74.1, 85.2, 90.9, and 96.5%, respectively. All the composites showed enhanced activity compared to pristine CTS, and the existence of a synergy between GO and PCN when both were employed as support materials was observed. Based on the charge carrier recombination characteristics and the band edge potential calculations from the composites, a possible mechanism of action of each composite was proposed. This study therefore confirms the possibility of modulating the mechanism of action and subsequently the efficiency of semiconductor materials by altering the nature of the support material.

Facile One‐Pot Synthesis and Enhanced Photocatalytic Performances of Ternary Metal Sulfide Composite g‐C3N4/Cu3SnS4

“…Similar situation was observed for the protonated graphitic carbon nitride (PCN) supported Cu 3 SnS4 composite (PCN‐CTS). The CTS‐PCN composite showed higher catalytic efficiencies in the degradation of tetracycline in comparison to pristine CTS and PCN [37] . The catalytic activities of CN/CTS composites is related with the loading amount of CTS.…”

“…The CTS-PCN composite showed higher catalytic efficiencies in the degradation of tetracycline in comparison to pristine CTS and PCN. [37] The catalytic activities of CN/CTS composites is related with the loading amount of CTS. As shown in Figure 6a, the photocatalytic efficiencies are in the order of CN/10 %-CTS (82.7 %) > CN/15 %-CTS (68.8 %) > CN/5 %-CTS (63.5 %) > CN/20 %-CTS (59.3 %) after 3.5 h light irradiation.…”

“…The CTS‐POM heterojunction performed much higher photocatalytic activities than CTS in the degradation of rhodamine B (RhB) under visible light irradiation, and the 5 % POM‐loaded CTS microspheres reached the best photocatalytic activity in H 2 production [36] . The PCN supported Cu 3 SnS 4 composite (PCN‐CTS) showed effective activity in the degradation of tetracycline [37] …”

“…They have been widely used in solar cells, photocatalysis, and hydrogen evolution reactions. [30,31] CTSs have been combined with graphene oxide (GO) or reducing-graphene oxide (rGO), [32,33] nanotitanium dioxide (TiO 2 ), [34] amorphous carbon (C), [35] Keggin-type polyoxometalate (POM), [36] and protonated graphitic carbon nitride (PCN), [37] to construct related heterojunctions or heterogeneous composites. These heterojunctions and composites showed excellent photocatalytic activities in the photodegradation of organic dyes or photocatalytic H 2 generation.…”

“…[36] The PCN supported Cu 3 SnS 4 composite (PCN-CTS) showed effective activity in the degradation of tetracycline. [37] g-C 3 N 4 is a typical 2-dimensional polymeric semiconductor photocatalyst. But its application is limited due to the moderate bandgap, the high recombination rate of photoinduced electron-hole pair and low utilization efficiency of visible light.…”