Morphology-dependent visible light photocatalysis

Due to the depletion of fossil fuels from the earth's crust leading to shortages of fuel for human activities, and the threatens by the increased environmental pollutions (water, air, and soil) lead by the unconventional discarding practices, cracking of fuels, etc., it has become crucial to seek out an alternative ecofriendly pathway to mitigate the issues related to the energy and environmental crises. In this regard, photocatalysis is being considered as an emerging technique for both power generation and environmental remediation. However, at present most large-scale or industrially acceptable photocatalysis is being attempted only under UV-light irradiation. This is due to the availability of mainly UV-active nanostructured materials to be used for efficient photocatalysis. The Sun, being a natural power source containing nonhazardous visible light (at least eight times more than its UV counterpart), is essential to use for green solar photocatalysis. To ensure visible light photocatalysis, attempts are being made to develop visible light-active photocatalyst materials. Light absorption is a surface property of these materials, and in addition to the synthesis of various new materials, altering the morphology of these new materials or existing materials (used under UV-irradiation) may contribute to efficient visible light photocatalysis. In this chapter, we attempt to discuss morphology-dependent visible light photocatalysis. In this regard, the basic concepts, present trends, and future scope are included.