煤的燃烧发电伴随有大量污染物和温室气体的产生，因此开发煤炭的新型绿色发电模式具有重要意义。水伏发电技术是利用材料与流体界面的相互作用来产生电能的新型发电模式，因其绿色、可持续和低成本的优势在近年来引起了研究人员的广泛关注。以煤粉为原材料，通过氧化改性调控煤粉表面的含氧官能度，利用抽滤的方法制备了改性煤粉/滤纸复合材料，组装了基于改性煤粉的蒸发发电装置。当器件被浸入水中时，水分子在蒸发和毛细力作用下由煤粉/滤纸复合膜底部向上定向传输，同时在表面呈电负性的氧化煤粉堆叠形成的通道中不断解离，氧化改性煤粉可排斥带相同电荷的阴离子而吸引带相反电荷的阳离子并在煤粉−水流表面形成双电层，流体中的离子因为移动速率的差异会在其传输的上下游位置分别形成阳离子和阴离子富集的区域并由此产生持续的流动电势。采用傅里叶红外光谱仪和纳米粒度分析仪对煤粉表面含氧官能团进行了表征。采用扫描电子显微镜对复合材料的微观形貌进行了观察。利用数字源表对器件发电性能进行了测试。当结合不对称电极工作时，其在纯水中工作能够产生高达0.72 V的电压，输出电流为0.4 μA，输出功率最高达到29.28 μW/m²。以改性煤粉制作的发电机还克服了传统水伏发电机在高浓度盐溶液中发电性能下降的问题，经测试，在浓度为1 mol/L的NaCl溶液中依然可以保持0.9 V的稳定输出电压。通过多个水伏发电装置的串联还可实现对低耗能装置的供电，展现了其潜在应用价值。

The combustion of coal for power generation is accompanied by the production of large amounts of pollutants and greenhouse gases. Therefore, the development of new green power generation methods for coal is of great significance. Hydrovoltaic power generation technology is a novel type of power generation mode that utilizes the interaction between materials and fluid interfaces to generate electrical energy. Increasing interests have been devoted into this area in recent years due to its economical and low-cost merits. This paper presents a novel coal powders (CP) based hydrovoltaic power generator. By regulating the oxygen-containing groups on the surface of the coal powder through oxidation modification, the interactions between coal powder and water molecules can be effectively improved. Combining with a filtration method, modified coal powder/filter paper composite was prepared to assemble a steam-based hydrovoltaic power generator. When the device is immersed in the solution, the water would flow through the bottom of the coal powder/filter paper composite membrane, driven by the effects of evaporation and capillary force. During which, water molecules dissociate continuously within the channels formed by the stacked oxidized coal powders. These negatively charged coal powders lead to the repulsion of anions while attracting cations inside the solution. As a consequence, an electrical double layer is formed on the surface of the coal powder-water flow interfaces. The directed flow of water causes a discrepancy in the migration rate between anions and cations, thereby generating continuous streaming potential. The oxygen functional groups on the surface of the coal powder were characterized using Fourier transform infrared spectrometer and a nanosize particle analyzer. The microstructure of the composite material was observed using scanning electron microscope. The power generation performance of the device was tested using a digital source meter. With the combination of asymmetric electrodes, it can generate a voltage of up to 0.72 V and an output current of 0.4 μA in pure water, with a maximum output power of 29.28 μW/m². The power generator made from modified coal powder also overcomes the problem of decreased power generation performance in traditional hydrovoltaic generators in high-concentration salt solutions. It can still maintain a stable output voltage of 0.9 V in a 1 mol/L NaCl solution. By connecting multiple hydrovoltaic power generation devices in series, it can directly drive low-power devices, demonstrating its promising potentials.