Aqueous-Based Synthesis of Photocatalytic Copper Sulfide Using Sulfur Waste as Sulfurizing Agent

Abstract

Most of the copper sulfide synthetic approaches developed until now are still facing issues in their procedure, such as long synthesis duration, high energetic consumption, and high implementation costs. This publication reports a facile and sustainable approach for synthesizing copper sulfides on a large scale. In particular, an industrial by-product of sulfur waste was used as a sulfurizing agent for copper sulfide synthesis in a water medium. The reaction was performed in the hydrothermal environment by following a novel proposed mechanism of copper sulfide formation. The investigation of morphological and optical properties revealed that the target products obtained by using waste possess the resembling properties as the ones synthesized from the most conventional sulfurizing agent. Since the determined band gap of synthesis products varied from 1.72 to 1.81 eV, the photocatalytic properties, triggered under visible light irradiation, were also investigated by degrading the methylene blue as a model pollutant. Importantly, the degradation efficiency of the copper sulfide synthesized from sulfur waste was equivalent to a sample obtained from a reference sulfurizing agent since the value for both samples was 96% in 180 min. This very simple synthetic approach opens up a new way for large-scale sustainable production of visible-light-driven photocatalysts for water purification from organic pollutants.

Sustainable PHBV/CuS Composite Obtained from Waste Valorization for Wastewater Purification by Visible Light‐Activated Photocatalytic Activity

“…On the other hand, when reference and waste photocatalysts are embedded in films, the degradation rate reaches a value 1.4 times higher with CuS particles obtained from waste (CuSw/Fi sample – 0.5203 min −1 ; CuSr/Fi – 0.3834 min −1 ) (Figure 2C,D). It is known from previous work [ 35 ] that CuSw has a larger crystallite average size than CuSr (39 and 35 nm, respectively), which can result in a higher degradation rate as reported by Goktas et al. [ 36 ] in their work on ZnO.…”

“…The added CuS is synthesized by using industrial sulfur waste as a sulfuring agent, according to the method previously reported. [ 35 ] In order to validate the applicability as a waste‐based photocatalyst (CuSw), we have also synthesized a reference sample of CuS by using pure sulfur, as a standard sulfurizing agent (CuSr, reference sample). The photocatalytic activity in the degradation of TC (50 mg L −1 ) of both photocatalysts has been tested.…”

“…This data corresponds perfectly with the composition of powder CuS samples reported in detail in our previous work, also proving that no new compounds were formed between polymer and photocatalyst. [ 35 ] Furthermore, all samples have been initially analyzed by field emission scanning electron microscope (FE‐SEM) to investigate both the dispersion and distribution of the incorporated photocatalyst (CuS) and the formation of the desired porous structure by TIPS. Figure 1 displays the top‐view FE‐SEM images of film and porous composites recorded with backscattered electrons to better highlight the inorganic particles from the surrounding polymeric matrix.…”

“…A detailed description of CuS synthesis is previously reported elsewhere. [35] Dry MFC was used as a hydrophilicity enhancer, which was produced by a previously established method reported elsewhere. [45] Chloroform (CHCl Samples Preparation: The porous composites were prepared by dispersing CuS particles (15 wt% with respect to the polymer) in a purified PHBV/DIOX solution (1.08 g of PHBV in 30 mL of solvent).…”

“…A detailed description of CuS synthesis is previously reported elsewhere. [ 35 ] Dry MFC was used as a hydrophilicity enhancer, which was produced by a previously established method reported elsewhere. [ 45 ]…”