Core–shell ZIF-67@Co-MOF-74 catalysts with improved photocatalytic properties were synthesized via the ligand exchange method.

The synergistic catalysis of bimetallic catalysts is one of the important ways to improve the catalytic performance; therefore, the development of efficient bimetallic water oxidation catalysts (WOCs) has received extensive attention. This work proposed a bimetallic Fe 3 O 4 /CuO catalyst prepared in situ from the Cu−Fe Prussian blue analogues precursor, promoting Fe 3 O 4modified CuO as a highly efficient and stable bimetallic WOC. The Fe 3 O 4 /CuO exhibits superior and robust catalytic activity for the oxidation of water. Compared with the reported results, it has a higher O 2 evolution rate of about 4406 μmol•h −1 •g −1 and a maximum value for the yield of O 2 as 83.2%, mainly because of the synergetic effect between Fe 3 O 4 and CuO in the complicated water oxidation reaction (WOR) process. We hope this work will be useful for other researchers to design new transition metal bimetallic catalysts for WOR.

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the exploration of advanced water treatment technologies e.g. heterogeneous photocatalysis is the most promising way to address organic pollution issues. Semiconductors based bimetallic photocatalysis with wide bandgap, have displayed splendid degradation performance in the UV light region, but their extension to the visible light/near infra-red region is still a matter of great concern. cuo, co(oH) 2 , coo and co(oH) 2 /cuo nanocomposites were synthesized via simple co-precipitation method and further practiced for Rhodamine B (RhB) decomposition by introducing per-sulfate (pS) as a sacrificial agent. Results revealed that Co(OH) 2 /cuo catalyst had shown robust catalytic activity for RhB photodegradation (degradation time 8 min, k = 0.864 min −1) under light illumination, significantly less (12-60 times) than the other reported bimetallic catalysts. Catalyst also have verified excellent performance for a broader pH range (5-9) with excellent stability. Main reactive species responsible for the photocatalytic reaction were sulfate (So 4 •−) and superoxide (o 2 •) radicals, duly verified by ESR and by using radical scavengers. With outstanding recycling abilities, this is probably the fewer successful attempt for RhB decolorization and can be highly favorable for effluent treatment by using the synergic effect of absorption and photodegradation. Globally increased population resulting in escalating environmental pollution, particularly, water contamination is consistently grabbing attention of researchers to overcome the needs of clean and safe water sources, for many decades 1. Ever-increasing garbage and effluents of many industries especially the usage of synthetic dyes in textile, tannery, paint, and paper industries are continuous sources of contaminated water 2. Releasing these dyes into the water sources, affecting aquatic life, ecosystems and human beings, adversely 3. Thus, the exploration of new and effective ways to overwhelmed organic water pollution issues is always considered as challenging. Many biological, physical, chemical, electrical and electrochemical methodologies have been developed, so far, for the removal of organic matter 4. From these methodologies, advanced oxidation processes (AOPs) have been extensively employed because of their simple, efficient and feasible approach. Amongst AOPs, heterogeneous photocatalysis has remarkable potential for organic pollutant removal, also has eco-friendly behavior, good stability, efficient photocatalytic activity for various dyes and most advantageously their economical and simple synthesis 5. Many techniques including sol-gel 6 , co-precipitation 7 , soluble sacrificial salt template 8 , solvothermal 9 and microwave-assisted approach 10 have been extensively attempted for the synthesis of facile and economical metallic catalysts. Rhodamine B is a widely used colorant in dyeing, textiles and food sectors, although it's banned, but still practiced in food factories, and also a good water tracer fluorescent 11. The carcinogenicity of RhB causes serious...

Composites of low dielectric constant SiO2, Au and metal oxide was obtained, it showed higher O2 evolution performance due to enhancing the electron transfer rate.