Assembly of Copper Phthalocyanine on TiO 2 Nanorod Arrays as Co-catalyst for Enhanced Photoelectrochemical Water Splitting

A photoelectrochemical device was achieved by interfacial self-assembly of macrocyclic π-conjugated copper phthalocyanine (CuPc) on surface of TiO nanorod arrays (NRs). The photocurrent density of the elegant TiO @CuPc NRs photoanode reaches 2.40 mA/cm at 1.23 V vs. RHE under the illumination of 100 mW/cm from AM 1.5G sun simulator, which is 2.4 times higher than that of the pure TiO . At the same time, the photoelectrochemical device constructed through this strategy has good stability and the photocurrent density remain almost no decline after 8 h of continuous operation. The Mott-Schottky and LSV curves demonstrate that CuPc act as a co-catalyst for water oxidation and a possible mechanism is proposed for water oxidation based on careful analysis of the detailed results. The holes from VB of TiO photogenerated by electrons exciting are consumed by a process in which Cu is oxidized to Cu and Cu , and then oxidize water to produce oxygen. CuPc species is considered to be a fast redox mediator to reduce the activation energy of water oxidation in and effectively promote charge separation.