Silicon Photoelectrodes Prepared by Low-Cost Wet Methods for Solar Photoelectrocatalysis

ConspectusThe electrochemical conversion of sunlight by photoelectrochemical cells (PECs) is based on semiconductor electrodes that are interfaced with a liquid electrolyte. This approach highly promising, first, because it can be employed for the generation chemical fuel (e.g., H2) to store solar energy used on-demand generate electricity when sun not available. Second, seen as concept reminiscent photosynthesis, where CO2 converted into valuable feedstock energy. Thus, sometimes referred “artificial leaves”. Silicon, being main in electronics and photovoltaic sector, prime candidate light absorber substrate building cells. However, Si alone has “poor-to-no performance”. caused its weak electrocatalytic activity cathodic reactions (namely, hydrogen evolution reaction (HER), reduction (CDRR), N2 reaction) deactivation anodic regime, prohibiting use oxygen (OER). latter essential supplying electrons fuel. Due these problems, layers both protect catalytically active typically photoelectrodes but require rather sophisticated manufacturing processes atomic layer or electron beam deposition), which hinders research innovation this field. Nevertheless, our group others have demonstrated always required stable Si-based manufactured using simple wet processes, such drop casting, electroless deposition, aqueous electrodeposition. In Account, we first introduce topic possible structures easily obtained starting from commercial wafers. Then, discuss strategies been manufacture photocathodes p-type Si. Among these, describe coated metal, inorganic compounds metal sulfides, more original constructs, those macromolecules composed catalytic Mo3S4 core polyoxometallate macrocycle. Also, elaboration advantages grafting organometallic catalysts promising candidates reaching excellent selectivity CDRR. photoanodes n-Si reviewed an emphasis prepared electrodeposition transition Ni Fe. The effect catalyst morphology, density, structuration discussed, future developments proposed.