Efficient photoelectrocatalytic performance of beta-cyclodextrin/graphene composite and effect of Cl- in water: degradation for bromophenol blue as a case study

Photoelectrocatalytic technology has proven to be an efficient way of degrading organic contaminants, including dyes. Graphene (GR) -based catalysts have been frequently used in photoelectrocatalysis, due to their excellent catalytic performances. In this work, the GR/beta-cyclodextrin (GR/beta-CD) composite was prepared and used for a widely used triphenylmethane dye (bromophenol blue, BPB) photoelectrocatalytic degradation. The results indicated that the degradation of the prepared GR/beta-CD composite for BPB was effective with the combination of external bias voltage and simulated sunlight irradiation. Under optimum conditions, the BPB (10 mg L-1) was completely eliminated by GR/beta-CD composite within 120 min. O-2(-) played a prominent role in the BPB photoelectrocatalytic degradation. The time required for the removal of BPB in water to reach 100% can be reduced to 30 min with the presence of Cl-, owing to the generation of Cl. Moreover, the toxicity of the degraded system with Cl-, predicted by the QSAR (Quantitative Structure-Activity Relationship) model in ECOSAR (Ecological Structure-Activity Relationships) program, was weaker than that without Cl-. The prepared GR/beta-CD composite revealed great advantages in photoelectrocatalytic degradation of organic pollutants due to its metal-free, low cost, simplicity, and efficient performance. This work provided new insight into the efficient and safe degradation of organic pollutants in wastewaters.

Automated summary

The study investigated the degradation of triphenylmethane dye using graphene/beta-cyclodextrin composite in a photoelectrocatalytic process. The results demonstrated that the composite effectively eliminated the dye under external bias voltage and sunlight irradiation, showing promising potential for applications in organic pollutant degradation.