Application of photo catalysis for mitigation of carbon dioxide

Photocatalytic reduction of carbon dioxide in alkaline medium on La modified sodium tantalate with different co-catalysts under UV–Visible radiation

“…Activity of the catalysts in UV visible region (300-700 nm) was evaluated in batch mode using jacketed all glass reactor (620 ml) [25] fitted with quartz window (5 cm dia) and filled with 400 ml of aqueous 0.2 mol L −1 NaOH solution. Besides increasing the solubility of CO 2 , alkaline solution acts as scavenger of holes.…”

“…Several photo-active semiconductors like TiO 2 , SiC, CdS, mixed metal oxides like InNbO 4 , HNb 3 O 8 , Bi 2 WO 6 , promoted NaNbO 3 , promoted Zn 2 GeO 4 and a number of layered titanates have been explored for this process [10][11][12][13][14][15]. Layered perovskite type oxides, like, ALa 4 Ti 4 O 15 (A = Ca, Sr, Ba) with Ag, Au, Ru, CuO and NiO as co-catalysts have been reported to be active for photo-catalytic reduction of CO 2 to CO and HCOOH [16].…”

Reduction of Carbon Dioxide: Photo-Catalytic Route to Solar Fuels

“…Such changes lead to increase in activity for water splitting as well as CO 2 photo-reduction. The location of the conduction band of NiO (at À0.96 eV) with respect to that of NaTaO 3 (at À1.06 eV) facilitates easy transfer of photo-generated electrons from Na (1Àx) La x TaO (3+x) to the conduction band of NiO [53]. Increase in the availability of photo-generated electrons in the conduction band of NiO facilitates deeper reduction of CO 2 to alcohols.…”

“…In spite of intense research in the past over four decades, the progress made appears to be marginal in terms of the activity of the systems considered. It is always necessary that in frontier areas of research like the carbon dioxide reduction to chemicals and fuels, one has to periodically assess the progress so that the diversions can be avoided and the goal can be achieved [25][26][27][28]. The activation of carbon dioxide (a linear molecule) is difficult and the initial step of adding an electron to form CO 2 anion radical is a high energy barrier step requiring an over-potential of 1.9 V. The subsequent steps to form products like CO, HCHO, HCOOH, CH 3 OH, CH 4 and other coupled products do not experience similar kind of barrier, even though the mechanistic details of these subsequent steps are still not fully revealed.…”

Turning lipophilic phthalocyanines/TiO2 composites into efficient photocatalysts for the conversion of CO2 into formic acid under UV–vis light irradiation

“…Although TiO 2 suffers from a relatively large band gap as well as from a massive recombination of photogenerated charge carriers, which limit its overall photocatalytic efficiency, modification of its band gap has become a well-established strategy that provides the additional benefit of conducting reactions under visible or solar light irradiation [11][12][13].…”