Interface Engineering of MoS<sub>2</sub>‐Modified Graphitic Carbon Nitride Nano‐photocatalysts for an Efficient Hydrogen Evolution Reaction
Eirini D. Koutsouroubi, Ioannis Vamvasakis, Ioannis T. Papadas, Charalampos Drivas, Stelios A. Choulis, Στέλλα Κέννου, Gerasimos S. Armatas
Abstract
Abstract Understanding of photochemical charge transfer processes at nanoscale heterojunctions is essential in developing effective catalysts. Here, we utilize a controllable synthesis method and a combination of optical absorption, photoluminescence, and electrochemical impedance spectroscopic studies to investigate the effect of MoS 2 nanosheet lateral dimension and edge length size on the photochemical behavior of MoS 2 ‐modified graphitic carbon nitride (g‐C 3 N 4 ) heterojunctions. These nano‐heterostructures, which comprise interlayer junctions with variable area (i. e., MoS 2 lateral size ranges from 18 nm to 52 nm), provide a size‐tunable interfacial charge transfer through the MoS 2 /g‐C 3 N 4 contacts, while exposing a large fraction of surface MoS 2 edge sites available for the hydrogen evolution reaction. Importantly, modification of g‐C 3 N 4 with MoS 2 layers of 39±5 nm lateral size (20 wt % loading) creates interfacial contacts with relatively large number of MoS 2 edge sites and efficient electronic transport phenomena, yielding a high photocatalytic H 2 ‐production activity of 1497 μmol h −1 g cat −1 and an apparent QY of 3.3 % at 410 nm light irradiation. This study thus offers a design strategy to improve light energy conversion efficiency of catalysts by engineering interfaces at the nanoscale in 2D‐layered heterojunction materials.