Photocatalytic conversion of CO2using ZnO semiconductor is an effective, simple, economicaland attractive way of combating energy problems resulting from anthropogenic emissions of CO2i.e. greenhouse gases to the atmosphere. This article focuses on current advances in CO2photoreduction by hydrothermal method. The fundamental photocatalytic CO2reduction systemby photocatalystsespecially ZnO has been explicated. The synthetic protocol of ZnO and itsgrowth mechanism in alkaline solution is elaborated with specific illustration of defect chemistryand its influence on CO2reduction activity and selectivity. Conclusively, brief challenges of itscurrent state and future prospects were also discussed
