Solar‐Driven Interfacial Evaporation and Self‐Powered Water Wave Detection Based on an All‐Cellulose Monolithic Design

Solar‐driven interfacial evaporation is an emerging technology with a strong potential for applications in water distillation and desalination. However, the high‐cost, complex fabrication, leaching, and disposal of synthetic materials remain the major roadblocks toward large‐scale applications. Herein, the benefits offered by renewable bacterial cellulose (BC) are considered and an all‐cellulose‐based interfacial steam generator is developed. In this monolithic design, three BC‐based aerogels are fabricated and integrated to endow the 3D steam generator with well‐defined hybrid structures and several self‐contained properties of lightweight, efficient evaporation, and good durability. Under 1 sun, the interfacial steam generator delivers high water evaporation rates of 1.82 and 4.32 kg m−2 h−1 under calm and light air conditions, respectively. These results are among the best‐performing interfacial steam generators, and surpass a majority of devices constructed from cellulose and other biopolymers. Importantly, the first example of integrating solar‐driven interfacial evaporation with water wave detection is also demonstrated by introducing a self‐powered triboelectric nanogenerator (TENG). This work highlights the potential of developing biopolymer‐based, eco‐friendly, and durable steam generators, not merely scaling up sustainable clean water production, but also discovering new functions for detecting wave parameters of surface water. A 3D monolithic interfacial steam generator is constructed from bacterial cellulose‐based nanofibrils, demonstrating high‐performance solar‐driven water evaporation, desalination, and self‐powered water wave detection.