Diminishing fossil fuels and global warming issues have forced the scientists to look for alternate sources of energy to cater to the ever increasing demand. Artificial systems are being developed in order to mimic natural photosynthesis and directly harvest and convert solar energy into renewable energy and environmental remediation. Despite significant efforts, it has been not possible to design a single material which has sufficient efficiency, stability and low cost. To integrate the desired characteristics in a single component, heterogeneous photocatalysts are designed with multiple functional components which could combine the advantages of different components to overcome the drawbacks of single component photocatalysts. The present highlight gives a concise overview of heterogeneous catalysts that have been developed and studied in our group and some excellent works of others in recent years. The review focuses on the principles of photocatalytic and electrocatalytic activity followed by the some key examples of oxide based materials. This includes a wide range of structural modification and crystal growth leading to composites, heterostructures, including insulator/semiconductor, semiconductor/semiconductor, and multi-hetero nanostructures and core-shell nanostructures which have been modified in order to improve the performance by increasing the light absorption, promoting the charge separation and transportation, enhancing the redox catalytic activity and intrinsic electrocatalytic properties. The electrochemical processes like hydrogen