Lead‐Free Perovskite‐Based Photocatalysts for Solar‐Driven Chemistry Technologies.

The high consumption of fossil fuels and concomitant contamination of the environment have promoted the search for new, low‐cost, and cleaner energy sources to satisfy the current energy demand around the world, decreasing the levels of greenhouse gas emissions to the atmosphere. One of the promising strategies to facilitate the generation of renewable energy involves solar‐driven chemical reactions, by using photocatalysts with improved sunlight absorption and carrier transfer abilities. Lead‐free halide perovskites (LFHPs) are good candidates, showing mesmerizing optical features, modulable band structure, oxidizing/reducing capability, and less toxicity compared to their Pb‐analogous. However, the literature reporting the photo(electro)chemical (PEC) properties of the LFHPs‐based materials for solar energy production is scarce. This review describes the current state‐of‐the‐art exhibiting the influence of the dimensionality, chemical composition and the formation of heterojunctions based on LFHPs on their photo(electro)activity for conducting solar‐driven hydrogen evolution, carbon dioxide (CO2) reduction, and the degradation of recalcitrant pollutants to obtain added‐value chemicals. In this way, it is also included the main challenges to be faced. Furthermore, we address some potential LFHPs to be explored in PEC systems, opening up the gamut of possibilities to consolidate the solar‐to‐chemical transformation as an innovative alternative to favor environmentally friendly energy production. [ABSTRACT FROM AUTHOR]