Freestanding single layers of non-layered material γ-Ga2O3 as an efficient photocatalyst for overall water splitting
Single layer nanosheets as an emerging class of new materials with intriguing properties for the potential applications in optoelectronic and catalysis were widely investigated in recent years. However, these nanosheets were only confined to the layered materials with the out-of-plate weak van der Waals bonds, and the non-layered materials were almost impossible to achieve the single layer nanosheets through the exfoliation procedure. Here, we fabricated the freestanding single layer nanosheets of non-layered material γ-Ga2O3 with unprecedented thickness (~1.25 nm) by a facile hydrothermal method without using any kind of shape control agents. The structural stability of single layer γ-Ga2O3 nanosheets was original from the surface distortion and hydroxyl group passivation. The prepared single layer γ-Ga2O3 nanosheets can enhance photocatalytic efficiency of water splitting and durably photocatalyze overall water splitting into hydrogen and oxygen. For comparison, the common bulk γ-Ga2O3 samples were silent for oxygen evolution in the same case. This work opens the door for extending atomically thick 2D nanosheets to non-layered compounds and holds promise for bringing on series of unprecedented excellent properties.