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 m(2) 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 mu m (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 x 10(-3) min(-1), which was twice as that of P25/CA and around twenty times that of 50 nm{001} TiO2/FTO. (C) 2014 Elsevier Ltd. All rights reserved.