Solar-driven interface evaporation has received much attention due to its high-efficiency photothermal conversion efficiency. However, in practical application, it is difficult to monitor whether the evaporation efficiency of photothermal conversion materials can maintain high efficiency and stability for a long time. In this paper, taking surface modified coconut fiber (SCF) as photothermal material, we designed a set of evaporation efficiency monitoring device (EEMD) and demonstrated the strategy of building a solar evaporation efficiency monitoring system. The SCF shows superhydrophilic wettability, and its vertical multi-stage open-framework structure is benefit to the rapid transport of water. Under 1 kW m⁻² illumination, evaporation rate of SCF is 1.5 kg m⁻² h⁻¹, evaporation efficiency is 90.2%. In 20% NaCl, evaporation rate of SCF is 1.37 kg m⁻² h⁻¹, and energy conversion efficiency is 85.3%. In order to monitor the stability of evaporator efficiency, we designed a simple EEMD which applied platinum wire electrode to monitor the change of electric potential in the evaporator. The results show that the electric potential is positively correlated with the evaporation efficiency. EEMD provides a new monitoring method for the efficient and stable operation of solar evaporator.

太阳能驱动的界面蒸发由于其高效的光热转换效率而备受关注。但是，在实际应用中，很难监测光热转换材料的蒸发效率是否可以长时间保持高效率和稳定性。本文以表面改性椰子纤维（SCF）为光热材料，设计了一套蒸发效率监测装置（EEMD），并论证了构建太阳蒸发效率监测系统的策略。SCF具有超亲水性的润湿性，其垂直多级开放式框架结构有利于水的快速输送。在1 kW m ^-2的光照下，SCF的蒸发速率为1.5 kg m ^-2  h ^-1，蒸发效率为90.2％。在20％NaCl中，SCF的蒸发速率为1.37 kg m ^-2  h ^-1，能量转换效率为85.3％。为了监测蒸发器效率的稳定性，我们设计了一个简单的EEMD，它应用了铂丝电极来监测蒸发器中电势的变化。结果表明，电势与蒸发效率呈正相关。EEMD为太阳能蒸发器的高效稳定运行提供了一种新的监控方法。