A simple fabrication, microstructure, optical, photoluminescence and supercapacitive performances of MgMoO4/MgWO4 heterojunction micro/nanocomposites

摘要

A polyacrylamide gel method combined with low temperature calcination technology are used to synthesize the MgMoO4/MgWO4 micro/nanocomposites. MgMoO4 and MgWO4 were coupled to form a special heterojunction structure with (220) and (111) crystal planes. Microstructural analysis confirmed that the MgMoO4/MgWO4 micro/nanocomposites were composed of large flake particles and small nanoparticles. MgMoO4/MgWO4 heterojunction micro/nanocomposites could not change the optical band gap (Eg) value of MgMoO4 but enhanced the concentration of adsorbed oxygen in the system. Electrochemical performance analysis showed that the specific capacitance of MgMoO4/20 wt %MgWO4 micro/nanocomposites is 222 mA h g(-1). The supercapacitor performance of MgMoO4/MgWO4 heterojunction micro/nanocomposites depends strongly on the preparation method, element composition, specific surface area and the transfer and separation efficiency of charge carriers. Photoluminescence analysis shows that the MgMoO4/MgWO4 micro/nanocomposites exhibits a stronger emission peak than MgMoO4 at 524 nm due to the synergistic effect of the adsorbed oxygen concentration and the recombination rate of charge carriers.

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