Introduction: Environmental pollution, particularly from organic contaminants, poses a growing challenge to public health and the environment. Photocatalysis and electrocatalysis are promising technologies for pollutant degradation, and their integration can enhance the efficiency of this process. Metal–organic frameworks (MOFs) are of increasing interest for such applications due to their high surface area and tunable structure, which can improve both electrocatalytic and photocatalytic performance.
Methods: In this study, a bismuth-based MOF using a 2,6-dicarboxynaphthalene linker was synthesized on an FTO substrate modified with TiO2. The MOF was grown through a reflux reaction in DMF at 110°C for 12 hours. The electrode was characterized using morphological and spectroscopic techniques. Its electrochemical properties were evaluated using chronoamperometry, linear sweep voltammetry, and EIS analysis. Its active surface area and electron transfer coefficient were determined to assess its performance. Its catalytic efficiency was tested in a pH 7 Na2SO4 solution for rhodamine degradation, both in electrocatalytic and photo-electrocatalytic modes.
Results: SEM analysis showed a uniform MOF distribution on the FTO-TiO2 substrate, while FT-IR spectroscopy confirmed carboxylate formation, consistent with the MOF structure. Raman analysis validated the successful formation of MOF and demonstrated its stability post-experiment. Electrochemical tests showed that the Bi-MOF-modified electrodes had a larger electroactive surface area compared to bare TiO2/FTO electrodes. The EIS analysis provided insights into the charge resistance and electrochemical behavior of the system. The Bi-MOF system demonstrated excellent rhodamine degradation, with a photo-electrocatalytic performance surpassing electrocatalysis alone.
Conclusion: The MOF-modified system showed enhanced photo-electrocatalytic properties compared to bare TiO2/FTO electrodes, making it a promising candidate for environmental applications in organic pollutant degradation.
