Is it possible to utilize photoelectrochemical, photochemical and photocatalytic reactions to harvest sunlight to meet the energy needs of the society? – A critical evaluation

Today our society is not only meeting >81% of its energy needs but also generating >81% economy by burning fossil fuels. Fossil fuels are nothing but solar energy stored by plant leaves by using CO2 and water, which cannot sustain our civilization economic growth. Furthermore, they are generating global warming causing greenhouse CO2 gas a by-product. As a part of generating alternative renewable energy vectors, a lot of research has been carried out so far to harvest sunlight by using CO2 and water as energy storing materials in the form of chemical fuels by following photoelectrochemical (PEC), photochemical and photocatalytic routes. Although, so far a half-a-million research articles have been published on all these subjects, the one that can be practiced at industry with economic viability is yet to be reported. In this review article, i) all the so far published articles, ii) the kind of sunlight reaching the earth surface, iii) the kind of semiconducting materials developed or identified so far, iv) why no reported method is being practiced at industry today for solar energy harvesting in the form of chemical and/or solar fuels to meet the energy needs of the society except only thin film based surface related photocatalytic spontaneous energy none-storing reactions such as, self-cleaning surfaces, etc., have been critically analyzes and reported while citing all the relevant and recent references.