Catalysis Database

PHOTOCATALYTIC REDUCTION OF CARBON DIOXIDE IN CONJUNCTION WITH DECOMPOSITION OF WATER ON OXIDE SEMICONDUCTOR SURFACES (complete version)

K, Rajalakshmi (2011) PHOTOCATALYTIC REDUCTION OF CARBON DIOXIDE IN CONJUNCTION WITH DECOMPOSITION OF WATER ON OXIDE SEMICONDUCTOR SURFACES (complete version). Masters thesis, Indian Institute of Technology, Madras.

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Abstract

ABSTRACT KEY WORDS: Photocatalysis, CO2 reduction, TiO2, water splitting, layered perovskite,band gap. Carbon dioxide accounts for the largest share of the world’s greenhouse gas emissions. There is a growing need to mitigate CO2 emissions. Some of the strategies to mitigate CO2 emissions are energy conservation, carbon capture and storage and using CO2 as a raw material in chemical processes. Reactions involving CO2 typically require energy input and/or a high energy substrate. The energy source should be provided without producing more CO2, such as solar energy. One of the best routes to remedy CO2 is to transform it to hydrocarbons via photo reduction. There by, solar energy is transformed and stored as chemical energy. The most ideal and desirable process would then be the simultaneous reduction of CO2 and water to yield hydrocarbons, which essentially works out to artificial photosynthesis. Among various semiconductors, TiO2 is widely used in many photoinduced processes because of its comparatively low cost, low toxicity and its ability to resist photocorrosion. The effect of transition metal ion on TiO2 was studied for CO2 photoreduction. Addition of noble metal to TiO2 can change the distribution of electrons and they prevent the electron hole recombination, thereby enhancing the Photocatalytic efficiency of TiO2.Also the effect of coupling TiO2 with other metal oxide semiconductors ( CuO,NiO) for CO2 photoreduction was studied. Wide band gap semiconductor materials are the most suitable for CO2 photoreduction. Since water is used as the reductant, the catalyst should be capable of splitting water into hydrogen and oxygen. NiO/La:NaTaO3 showed high activity for water splitting and quantum efficiency of 56% was observed for this catalyst. Hence NiO/La:NaTaO3 was tested for CO2 photoreduction with water. Layered pervoskite such as Sr3Ti2O7 and NiO/Ba:La2Ti2O7 which was active towards water splitting were also tested for CO2 photoreduction.

Item Type:Thesis (Masters)
Subjects:Science > Chemistry
ID Code:1952
Deposited By:Prof Balasubramanian Viswanathan
Deposited On:18 Apr 2011 08:56
Last Modified:18 Apr 2011 08:56

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