A cadmium-imidazole coordination polymer as solid state buffering material: Synthesis, characterization and its use for photocatalytic degradation of ionic dyes
Abstract
A cadmium-imidazole coordination polymer (Cd-Im CP) was facilely synthesized in ethanol/aqueous solution at low temperature and was characterized using PXRD, FTIR, Raman, SEM/EDX and N2-BET analyses. Structure solution, performed by Reflex module/Materials Studio validated the coordination as [Cd(HIm/Im/OH)]n. Cd-Im CP was examined for its potential use to photocatalytically degrade the cationic dye methylene blue (MB) and the anionic dye methyl orange (MO) under properly selected UV light source (254 nm, 24 W) at different initial pH. Photocatalytic-degradation experiments revealed similar pH-degradation profile for both dyes where the highest degradation was recorded at nearly neutral pH of and rate constants were 0.0083 and 0.0047 min-1 for MB and MO respectively. Degradation analyses elucidate that Cd-Im CP has a buffering effect, a character that strongly impacted the degradation mechanism. Due to limited adsorption of dyes by Cd-Im CP, the proposed mechanism of degradation comprises diffusion of O2•- radicals toward the bulk solution where degradation occurs, meanwhile for basic and acidic conditions dyes' molecules diffuse toward Cd-Im CP surface where they experience collisional-interaction with O2•- nearby the Stern layer, and thereafter degradation follows known pathway.
- Publication:
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Journal of Solid State Chemistry France
- Pub Date:
- September 2020
- DOI:
- 10.1016/j.jssc.2020.121493
- Bibcode:
- 2020JSSCh.28921493M
- Keywords:
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- Cadmium-imidazole;
- Coordination polymer;
- Solid buffering;
- Photocatalytic degradation;
- Ionic dyes