Assembly of Copper Phthalocyanine on TiO₂ Nanorod Arrays as Co-catalyst for Enhanced Photoelectrochemical Water Splitting.

ABSTRACT: A photoelectrochemical device was achieved by interfacial self-assembly of macrocyclic ?-conjugated copper phthalocyanine (CuPc) on surface of TiO₂ nanorod arrays (NRs). The photocurrent density of the elegant TiO₂@CuPc NRs photoanode reaches 2.40 mA/cm² at 1.23 V vs. RHE under the illumination of 100 mW/cm² from AM 1.5G sun simulator, which is 2.4 times higher than that of the pure TiO₂. 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 TiO₂ photogenerated by electrons exciting are consumed by a process in which Cu²⁺ is oxidized to Cu³⁺ and Cu⁴⁺, 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.

SUBMITTER: Li Y 

PROVIDER: S-EPMC6530342 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature