Photocatalytic Generation of Hydrogen in Degrading Soluble Organic Pollutants with Metal-Ceramic Composites

Resumo

Phase composition and morphological specific features of metal-ceramic composites synthesized by the method of self-propagating synthesis from aluminum ferrosilicon with addition of modifiers (shungite, metallic titanium) was studied. The optical properties of the composites were examined, and the energy gap widths of the semiconductors constituents of the ceramic matrix were found from electronic absorption spectra. The efficiency of the processes of hydrogen generation from solutions of “sacrificial” reagents (carboxylic acids, hydrazine, and saccharose) was evaluated in relation to their concentration and H₂O₂ concentration, addition of a dye, and phase composition of the composites. It was shown that hydrogen is generated from the sacrificial reagents as a result of the combination of heterogeneous and homogeneous kinds of photocatalysis. The highest hydrogen evolution output (∼830 µmol g⁻¹ h⁻¹) was obtained from solutions of oxalic and malic acids.