Structure, Spectral and Photocatalytic Properties of Porous ZnO Nanopowders Modified by Oxide Compounds of Manganese

Abstract—Porous nanocomposites based on oxide compounds of zinc and manganese are synthesized, and their structure, morphology, spectral and photocatalytic properties are studied. The porous oxide composites have photocatalytic properties and consist of ZnO, Mn₃O₄, and ZnMn₂O₄ nanocrystals with sizes of 20–40 nm. The incorporation of Mn²⁺ ions into the ZnO crystal lattice causes a 0.9% increase in the unit cell volume. The band gap of the composites is 3.26 eV. The kinetics of photocatalytic degradation of Chicago Blue Sky dye in solution is described by a pseudo-first order equation. In the presence of porous nanocomposites, the oxidation of organic compounds proceeds both on the photocatalyst surface and in the solution bulk. The synthesized nanocomposites show promise for use in photocatalytic systems for water purification from organic contaminants and for water splitting to oxygen and hydrogen for hydrogen energy production.