General Review on the Components and Parameters of Photoelectrochemical System for CO 2 Reduction with in Situ Analysis

One of the promising renewable energy sources is converting CO 2 into useful chemical fuels; it will help to overcome both energy supply and global warming issues. Among various methods for CO 2 reduction, photoelectrochemical (PEC) CO 2 conversion is the most promising and easy method so far because it can be useful to control thermodynamics and kinetics of CO 2 reduction reaction for product selectivity and fast reaction kinetics by mimicking natural photosynthesis without high input energy cost. However, it has some limitation factors that create difficulties for widespread utilization. The detection of CO 2 products and intermediates on a small scale is another challenging part in this field. The small amount of the CO 2 product can be further oxidized or evaporated, which could be difficult to be detected. Therefore, an in situ technique is a good approach to study the proper reduction mechanism during the CO 2 reduction process. This review starts with basic concept of solar to fuel (STF) conversion by CO 2 reduction and covers various aspects related to photoelectrochemical CO 2 reduction. This main theme is completely depending on important parameters such as photoanode materials, photocathode materials, electrolyte solutions for photoelectrochemical CO 2 reduction with the most important in situ measurement techniques for product analysis.