Adsorption is a low-energy, economical, and efficient method for pollutant removal from water. Because of their unique structure, large specific surface area (SSA), and non-toxicity, bismuth-based semiconductors, usually researched for the photodegradation of organic molecules, are also excellent for dark adsorption processes. Here, a three-dimensional adsorbent with a heterostructure with a hydrangea-like shape made of Bi2MoO6(BMO) and BiOI (BOI) was synthesized by a one-pot solvothermal process and investigated for the adsorption of toxic dyes. BOI/BMO with an I-to-Mo ratio of 2.0 adsorbed 98.9% of the model pollutant rhodamine B (RhB) within 5 min with a maximum adsorption capacity of 72.72 mg/g in the dark at room temperature. When compared to pure BMO, the BOI2/BMO heterostructure was 14.1 times more performant because of its flower-like morphology with multiple planes, an SSA that was 1.6-fold larger, increased porosity, the formation of heterojunctions, and a negative surface charge attracting RhB. Further investigation indicated that adsorption by BOI2/BMO fitted the pseudo-second-order kinetic and the Langmuir isotherm models. In addition, the thermodynamic analysis showed that it was a spontaneous exothermic process probably relying on physisorption. Thus, the BOI/BMO adsorbent developed here is promising for the fast removal of toxic dyes from industrial wastewater.Keywords:BiOI/Bi2MoO6;heterostructure;rhodamine B;dark adsorption;kinetics;thermodynamic
This study focuses on a novel ternary heterojunction catalyst for the removal of 2,4-dichlorophenol (2,4-DCP), an organic pollutant that is difficult to degrade. An efficient CuInS 2 /BiOI/Bi 2 MoO 6 ternary heterojunction photocatalyst was formed by constructing a CuInS 2 /BiOI composite layer on a Bi 2 MoO 6 substrate using an in-situ growth technique. The microstructure and photoelectric conversion properties of the catalysts were comprehensively resolved by systematic material characterization, including scanning electron microscopy (SEM) observation, X-ray photoelectron spectroscopy (XPS) analysis and photoelectrochemical testing. The experimental results showed that the optimized catalyst at a loading of 2.0 g/L exhibited excellent photocatalytic degradation efficiency against 20 mg/L concentration of 2,4-DCP at neutral pH, reaching 80.3 % degradation rate in 120 min. This high performance was mainly attributed to the enhanced charge-carrier separation mechanism at the heterojunction interface, which effectively enhanced the utilization and transfer rate of photogenerated electron-hole pairs and enhanced the photocatalytic activity of the catalyst. In addition, the study also deeply explored the conversion pathway of elemental chlorine in the photocatalytic system, elucidated the mechanism of 2,4-DCP degradation and dechlorination, and provided a theoretical basis for further improving the environmental adaptability and dechlorination efficiency of the catalyst. Overall, the CuInS 2 /BiOI/Bi 2 MoO 6 ternary heterojunction photocatalysts proposed in this study demonstrate a broad application prospect in the purification of 2,4-DCP and other organic pollutants, and open up a new way to solve the problems of industrial wastewater treatment, which is of great environmental significance and scientific value.