Artificial Photosynthesis: Photocatalytic Conversion of CO2 into Hydrocarbon Fuels

Abstract

One of the major problems concerning environmental pollution and global warming is a rapid escalation in the level of carbon dioxide in atmosphere.The atmospheric CO2 level can be reduced by converting it into useful products via thermochemical and photochemical processes. Amongst these conversion processes, the photochemical conversion is an environment effective and preferred process for the photoreduction of CO2 into useful liquid fuels like methanol, formaldehyde, and methane gas. Photoreduction of CO2 into hydrocarbon fuels on the surface of photocatalyst is one of the breakthroughs in the field of photocatalysis. At present various approaches have been investigated with the aim of increasing the CO2 conversion efficiency. The reactor for photoconversion of CO2 plays a vital role in experimental setup. In first study an attempt was made to testify a newly designed the photoreactor for conversion of CO2 into useful products. The photoreactor was specifically designed for simple operation bearing features of temperature and pressure control. The reactor has been tested successively with the standard titania, Degussa P25 yielding methane with moderate production rate of 1007 μmol·g-1·h-1 (16.11 ppm·g-1·h-1). under UVB lamp (λmax = 365 nm). The methane yield obtained is comparable to the values reported in literature. In second study, CuO-TiO2 nanostructure, a hybrid material photocatalyst was synthesized and tested for CO2 photoreduction. The synthesis process involves the formation CuS nanostructure using electrochemical anodization followed by embedment of titanium isopropoxide as Ti precursor. The oxidation of the nanosctuctre is performed at temperature of 400 °C oxidizing Cu and Ti to form CuO-TiO2 nanostructures. ⓒ 2014 DGIST