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Description
Photocatalytic hydrogen production under solar light irradiation is an attractive technology to receive green and renewable fuel and thanks to natural resource usage and zero CO2 emission is among different technologies the greenest process. As a promising photocatalyst for hydrogen production TiO2 have been commonly used due to its special physicochemical properties. However, its wide bandgap energy, which can be only activated under UV-light and fast charge carrier recombination restricts its applications.
The initiative is based on the idea of the improvement of the visible light response
Summary of the results
The photocatalytic reduction of carbon dioxide under UV and Vis light excitation, resulting in carbon monoxide and methane as CO2 reduction products, and hydrogen formation from photocatalytic water splitting was studied. Generally a lower quantities of valuable green chemicals were noticed for titanium dioxide modified with nitrates, because recombination of photoexcited charge carriers occurs more rapidly in the Co,(Zn),(Mn),N-TiO2 systems than in the case of Pt-TiO2 and copper isopropoxide modified titanium dioxide. Modification with non-metal ions (in this case nitrogen) has been shown to give poor results. In contrast, the use of metal nanoparticles (platinum) or metal and non-metal (cobalt or copper and nitrogen) for modification improves activity as a result of slowing recombination of charge carriers. The photoelectrocatalytic properties were also investigated, and it was found that an optimal loading the sample with metal improves the amount and/or constancy of photoexcited currents due to the structural defects likely slowing the recombination rate of charge carriers. A toxicity assessment of the individual materials have been conducted. Two Cu containing materials being most toxic and showing a exposure concentration-response relationship (24 h) dependent on the Cu concentrations present in the materials (4.5% Cu > 2.5%Cu)