2D/2D Heterojunction of Ultrathin MXene/Bi2WO6 Nanosheets for Improved Photocatalytic CO2 Reduction. (6th April 2018) - Cao, Shaowen
Abstract: Exploring cheap and efficient cocatalysts for enhancing the performance of photocatalysts is a challenge in the energy conversion field. Herein, 2D ultrathin Ti3 C2 nanosheets, a kind of MXenes, are prepared by etching Ti3 AlC2 with subsequent ultrasonic exfoliation. A novel 2D/2D heterojunction of ultrathin Ti3 C2 /Bi2 WO6 nanosheets is then successfully prepared by in situ growth of Bi2 WO6 ultrathin nanosheets on the surface of these Ti3 C2 ultrathin nanosheets. The resultant Ti3 C2 /Bi2 WO6 hybrids exhibit a short charge transport distance and a large interface contact area, assuring excellent bulk‐to‐surface and interfacial charge transfer abilities. Meanwhile, the improved specific surface area and pore structure endow Ti3 C2 /Bi2 WO6 hybrids with an enhanced CO2 adsorption capability. As a result, the 2D/2D heterojunction of ultrathin Ti3 C2 /Bi2 WO6 nanosheets shows significant improvement on the performance of photocatalytic CO2 reduction under simulated solar irradiation. The total yield of CH4 and CH3 OH obtained on the optimized Ti3 C2 /Bi2 WO6 hybrid is 4.6 times that obtained on pristine Bi2 WO6 ultrathin nanosheets. This work provides a new protocol for constructing 2D/2D photocatalytic systems and demonstrates Ti3 C2 as a promising and cheap cocatalyst. Abstract : A 2D/2D heterojunction of ultrathin Ti3 C2 /Bi2 WO6 nanosheets with several atomic layers is constructed, showing remarkably enhanced performance toward photocatalytic CO2 reduction. The Ti3 C2 /Bi2 WO6 2D/2D heterojunction possesses a large interface contact area and a quite short charge transport distance, leading to efficient bulk‐to‐surface and interfacial electron transfer. Moreover, the 2D/2D heterojunction possesses a distinctly enhanced CO2 adsorption capability, which further boosts the photocatalytic reactions.