Photocatalytic degradation of rhodamine B based on membrane catalyst of H₃O₄₀PW₁₂/quaternized chitosan

Abstract

Increasing environmental pollution caused by toxic dyes due to their hazardous nature is a matter of great concern, and lacks the effective methods to remove them. Therefore, in this research a series of H3O40PW12/Quaternized chitosan (PWX%/QCS) membrane catalyst is synthesized based on QCS (positively charged) and keggin‐type H3O40PW12 (negatively charged), which is available to degrade rhodamine B. The optimum experimental conditions are investigated and results reveal that the degradation rate is over 92.1% and the chemical oxygen demand (COD) decreases is 78.09%, which is obtained based on the follow conditions is that the UV radiation is 90 min, the dose of membrane catalyst is 0.1g, the doping amount PW12 (H3O40PW12) is 35 wt%, RB aqueous solution (30mL) is 5mg/L, the reaction temperature is 30°C, pH = 5 and H2O2 is 20mM. The simulation result reveals that the photocatalytic degradation reaction of RB with PWX%/QCS membrane catalyst in an aqueous solution can be described by the Langmuir–Hinshelwood equation. And the initiation rate constant and the initiation adsorption constant in this case are 4.082mg/(L/min) and 0.01090L/mg, respectively.

Zwitterionic and Photocatalytic Janus Membrane Based on Diethylamine N-Oxide Group and WS2 Nanosheets for Dye Removal in Forward Osmosis

“…Moreover, RhB in the presence of H 2 O 2 and light shows a significant decrease in the initial concentration concerning the test without light, suggesting H 2 O 2 acting as a stimulant by generating OH radical species between 200 and 280 nm. Furthermore, the interaction between the RhB and ·OH radicals can produce RhB + species that can act as an additional oxidizer of the dye in the original sample. , Similar results were observed when the PSF-DEAO membrane was present; the slight increment in the removal can be attributed to the adsorption capacity of the membrane. When the Janus membrane is exposed to room light, the removal efficiency increases above 20% compared to the test without light.…”

“…Furthermore, the interaction between the RhB and •OH radicals can produce RhB + species that can act as an additional oxidizer of the dye in the original sample. 31,32 Similar results were observed when the PSF-DEAO membrane was present; the slight increment in the removal can be attributed to the adsorption capacity of the membrane. When the Janus membrane is exposed to room light, the removal efficiency increases above 20% compared to the test without light.…”

“…Therefore, this indicates that the reaction rate is directly proportional to the concentration of the RhB, as is evident in Figure S6b, and it is expected from first-order reactions. Photodegradation reactions involving organic dyes have been shown to follow first-order kinetics. − Thus, it is validated that the WS 2 nanosheet layer on the Janus membrane can act as a photocatalyst that induces the formation of ROS from hydrogen peroxide and dissolved oxygen.…”