Nanocatalysts have received much attention because of their vast applications in various organic pollutants removal as well as their selectivity, ease in separation, eradicating the expensive materials and hazardous chemicals. Nanocatalysts are the heart of scientific field because of their vast applications in multidisciplinary sciences. This chapter provided a brief knowledge using nanocatalyst for the removal of organic toxins, for instance nitrophenols and dyes, which are at alarming condition. The readers will be benefited from this chapter and will learn about photocatalysis and its application. The use of semiconductors is appropriate in photocatalysis, therefore, much information is available about semiconductor. An important morphological nanocatalyst is the layered double hydroxide; also worked as a solar catalyst for the removal of contaminants and various support are present for these material to enhance its catalytic performance. Supported materials in nanocatalysis are required to stabilize the nanoparticles (Nps) from being aggregated and also offer any easy route in separating the catalyst after the reaction. Such criteria are highly demanded at industrial level.