Abstract. In the development of renewable energy, the usage of solar cells, fuel cells, hydrogen energy, thermoelectric energy, and thermal energy has become a significant focus of research and development. Semiconductor nanomaterials play important roles in these fields. This paper focuses on the usage of TiO2 and In2O3 in renewable energy and finds out the trends and outlook of semiconductor nanomaterials in this field. TiO2 nanomaterials have attracted widespread attention due to their unique structure and excellent properties, such as their large specific surface area, high surface activity, and sensitivity. TiO2 nanomaterials are highly active in photovoltaic applications and play an important role in the search for renewable, clean energy technologies. In2O3 is an excellent n-type transparent semiconductor functional material, characterized by high sensitivity, low resistivity, good conductivity, high catalytic activity, and wide bandgap width. It has shown good competitiveness in gas sensors, solar cells, and photocatalysis fields. Although these semiconductor nanomaterials have many advantages, there are still some drawbacks that hinder their development. There is still much work to be done for the wider application of semiconductor nanomaterials in the field of renewable energy.