**Abstract**

Photocatalytic water splitting under irradiation of light is an ultimate system to make available renewable energy sources. However, significant efforts have been made to fabricate advanced nanocomposites; the major challenge persists, which is low efficiency and selectivity towards hydrogen evolution under the illumination of solar energy. In this chapter, the recent developments in photocatalysts, and heterojunction fabrication factors influencing the photocatalytic process for the dynamic production of hydrogen have been discussed. The improvements in photocatalyst systems have been classified as strategies to improve different factors of photocatalytic splitting such as Z-scheme systems and the influence of operating parameters such as band gap, morphology, temperature, oxygen vacancies, intensity, and pH. In addition, the thermodynamics of selective photocatalysts is conferred critically. The future research aspect of photocatalytic water splitting has been also discussed.

**Keywords:** water splitting, nanocomposite, photocatalyst
