In‐Situ Self‐Assembled ZnO Foam Based on Graphene‐Like Ultrathin Nanosheets

Abstract

AbstractIt is still a challenge to prepare 2D ultrathin ZnO in a simple method, especially for the in‐situ growth of 2D ultrathin ZnO on different substrates. Herein the ZnO foam with high specific surface area is successfully assembled in situ from graphene‐like ultrathin nanosheet on various substrates, including rigid fluoride doped tin oxide, Ni foam, and flexible indium tin oxide, carbon cloth, etc. The thickness of graphene‐like nanosheet is just ≈1.5 nm. The results reveal that the specific surface area of ZnO nanosheets is 90.7 m2 g−1. The high specific surface area of the hydrophilic ZnO foam and its in‐situ growth characteristic make it promising water channel in solar‐driven interfacial water evaporation system. By using a flexible carbon cloth/ZnO foam (C‐ZnO) Janus absorber, a high rate of water evaporation (2.4 kg m−2 h−1), which is 4.6 times higher than that of natural evaporation is demonstrated. This work provides a new method in the design of ZnO ultrathin nanosheets, what's more, the facile growth of the ZnO foam on various substrates make it possible for the application in optoelectronic devices.