Nanocrystalline {001} TiO2/carbon aerogel electrode with high surface area and enhanced photoelectrocatalytic oxidation capacity

Aiming at further developing the application of the highly reactive {001} TiO2 in photoelectrocatalytic oxidation, which is limited by the powder form, micron-size and low surface area, a nanocrystalline {001} TiO2/carbon aerogel (CA) photoelectrode was fabricated via a facile hydrothermal method. Nano-sized (50 nm) anatase {001} TiO2 was successfully grown on a CA substrate. The obtained photoelectrode endowed high surface area (537 m2 g−1) and enhanced photoelectrocatalytic oxidation performance. Under UV light illumination, the largest photocurrent density is obtained on 50 nm {001} TiO2 (5.58 mA cm−2), compared to 150 nm (4.17 mA cm−2), 1 μm (2.83 mA cm−2) {001} TiO2, indicating that an obvious enhancement in photoelectrocatalytic oxidation activity was achieved when crystalline size reached nanometer scale. A high methylene blue removal of 93% was obtained on 50 nm {001} TiO2/CA, and the rate constant reached 8.46 × 10−3 min−1, which was twice as that of P25/CA and around twenty times that of 50 nm{001} TiO2/FTO.