Recent developments in piezo-photocatalytic CO₂ reduction: concepts, mechanism, and advances

Out of the high number of photocatalytic applications, CO₂ reduction has proved to be quite a boon for the present world. Increasing CO₂ emissions owing to fossil fuel usage has been a menace to our society. To date, many methods have been developed to redress the situation. One of them is photocatalysis, which has been a well-known branch of energy and environmental applications since 1972. This is due to its low energy consumption and green nature. In recent years, a new phenomenon has come into existence wherein a combination of mechanical energy and photocatalysis can increase the efficiency of any catalytic process. In this regard, this frontier article will discuss the recent developments in piezo-photocatalysis for CO₂ reduction. The main focus will be understanding the underlying mechanisms of efficiency enhancements in photocatalytic systems. Initially, the mechanism of CO₂ reduction and its current needs will be discussed in the introduction. Further, a collection of recent reports from the literature and various material systems will be discussed to gain insights into the latest developments in the area. Then, literature and references that are purely mechanism-based with deeper analysis will be discussed, along with crucial characterization techniques for piezo-photocatalysts. Many factors need to be factored in for a better understanding of piezo-photocatalysis, e.g., factors such as piezo energy source, material design, and CO₂ adsorption, require more attention to increase the CO₂ reduction capability of photocatalysts. Based on the discussions in this article, researchers will gain new perceptions on the combination of vibrational energy and light energy to enhance CO₂ reduction yields. Moreover, this article can advance understanding of techniques such as Kelvin probe microscopy, the requirement of simulation studies, and CO₂ reduction mechanisms to better understand the piezo behavior of materials and ways to improve them for maximum product yield.