Facile fabrication of Co2P/TiO2 nanotube arrays photoelectrode for efficient methylene blue degradation

The TiO2 nanotube arrays (NTAs) modified by various contents of Co2P were synthesized through a two-step anodization-hydrothermal approach to degrade methylene blue (MB). Co2P nanoparticles (NPs) were uniformly deposited on the nozzle of TiO2 NTAs and used as a cocatalyst to transfer the holes, which could accelerate the separation of photogenerated carriers. The experimental results showed that the light absorption capacity, photocurrent density and degradation rate of TiO2 NTAs were improved after Co2P modification, and that the transient photocurrent density of 1.5-Co2P/TiO2 NTAs was about 3.22 times higher than that of pure TiO2 NTAs. Besides, 1.5-Co2P/TiO2NTAs also exhibited excellent activity during the photoelectrocatalytic degradation of MB. The trapping experiment was conducted to investigate the physicochemical properties of 1.5-Co2P/TiO2 NTAs. It was found that the enhanced activity might be attributed to the effective synergistic contribution of O-2(-) and center dot OH.