Application of Novel Calix[4]arene Metal-free Sensitizers in Dye-sensitized Photoelectrochemical Cells for Water Splitting

A series of novel calix[4]arene metal-free dyes,featuring macrocyclic structure and unique conical confor mation,has been introduced into photoanode-based dye-sensitized electrochemical cell system as photosensitizers.The electrochemical properties of the corresponding sensitized photoanodes were systematically studied in the absence.presence of water oxidation catalyst(WOC).Furthermore,the visible-light-driven overall water-splitting reactions wero conducted by fully assembled devices,obtaining a performance trend of Calix-3>Calix-2 Calix-1.The correspondins device of Calix-3 exhibited the best photoactivity,giving an initial photocurrent density of ca.300 pA/cm^2,an IPEC peak value of ca.9.0%at 365 nm and a wide photo-respond band up to ca.620 nm.The best performance of Calix-3 an be attributed to its most effective light-harvesting ability,best ICT transition property,highest oxidation potentiaand thus best ability of activating WOC.This work offers an inspiration for the application of new-type effective metal-free sensitizers in photocatalytic water-splitting device.