Formation and Properties of Heterosystems Based on Porous Silicon, Graphitic Carbon Nitride and Semiconductor Compounds

Abstract

The possibility of pyrolytic synthesis of composite heterosystems based on macroporous silicon, graphitic carbon nitride and wide band semiconductors zinc oxide and zinc sulfide (g-C3N4/ZnO/ZnS) from a mechanical mixture of thiourea and zinc acetate at 500 – 600 °C was shown. The obtained material study by scanning electron microscopy and energy dispersive X-ray spectroscopy showed a uniform filling of macroporous silicon with the composite g-C3N4/ZnO/ZnS with the formation of a continuous composite film on the surface. The photoluminescence of the samples was controlled by the synthesis temperature. Increase of photoluminescence leads to shift of luminescence maximum in high energy range from 544 to 516 nm. It was found that photocatalytic activity of composite heterosystems obtained at a lower temperature is higher due to more developed surface morphology and smaller bandgap width. The materials obtained can be used to create photocatalytic coatings and functional layers of optoelectronic devices.

Keywords

• graphitic carbon nitride
• zinc oxide
• zinc sulfide
• macroporous silicon
• photoluminescence
• photocatalysis
• scanning electron microscopy
• water purification