A photocatalyst is a substance that absorbs light. Upon absorbing light the photocatalyst gets excited and can give away electrons to molecules nearby that have a reduction potential close to the oxidation potential of the photocatalyst. The catalyst can regain the electron from a sacrificial electron donor.

This pathway is exploited such that alcohols are converted to an intermediate by the reaction conditions, then it would accept the electron from the photocatalyst and degrade into an alkane. In short, a photocatalyst converts an alcohol to an alkane by the energy that it receives from sunlight. It performs deoxygenation with simplicity.

The intermediate decomposes to a free radical, before converting to an alkane. This unstable free radical is also being used to form C-C bonds easily.

Oxygenated compounds form the intermediates in burning of fuel. Most of the energy is released from burning fuels because of their conversion to alcoholic compounds that if isolated, they can be converted to their deoxygenated versions which is fuel again. This way, fuel is burnt, and energy is obtained, and can be converted back to fuel due to sunlight using the above mentioned reaction.

A reaction intermediate or an intermediate is a molecular entity that is formed from the reactants (or preceding intermediates) and reacts further to give the directly observed products of a chemical reaction. Most chemical reactions are stepwise, that is they take more than one elementary step to complete. An intermediate is the reaction product of each of these steps, except for the last one, which forms the final product. Reactive intermediates are usually short lived and are very seldom isolated. Also, owing to the short lifetime, they do not remain in the product mixture.

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