Tribovoltaic nanogenerators (TVNGs) present great properties such as high direct‐current density and continuous output performance, which has great potential to solve the power supply problem for miniaturized electronic devices. However, the severe wear problem of TVNG causes rapid attenuation of current density, which is difficult to realize long‐term operation with high output. In this work, an effective strategy via interface lubrication is proposed to enhance the direct‐current density and lifetime of TVNGs simultaneously. The water‐based graphene oxide solution is utilized as a lubricant, which can increase the sliding surface carriers to enhance current density, and reduce the wear between the copper and the silicon wafer surface due to its excellent lubrication performance. Hence, the TVNG can generate peak current density output ≈775 mA m−2, accompanied with 31 mC m−2 transfer charges density. The TVNG via interface lubrication can maintain high current output after 30 000 cycles. In addition, it can combine with triboelectric nanogenerator to constitute a dual‐type signal sensor, which can be used to monitor bridge vibration and goods’ weight. This study provides an effective method to solve the wear problem of TVNG and improve direct‐current density simultaneously, which will accelerate the practical application of TVNGs in the future.

Although electrocoagulation technology has been widely researched in wastewater treatment, high energy consumption and electrode passivation are still the main challenges for its widespread applications. Here, we propose a self-powered electrocoagulation system based on a triboelectric nanogenerator (TENG) with alternating current (AC) outputs to solve these two issues, and thus enhance the removal efficiency of organic pollutants. Compared with the direct current source, the AC power source can reduce the electrode passivation, produce more aluminum hydroxide compounds after consuming an equal amount of charges, and thus improve the degradation efficiency. Moreover, the removal efficiency can be further enhanced by decreasing the frequency AC, in which a 5.7-fold improvement was achieved at 0.2 Hz compared to DC at 1.8 Hz. Inspired by the low frequency of ocean wave water, we developed a self-powered AC-electrocoagulation system to directly drive the electrocoagulation reaction by harvesting water wave energy, which can effectively remove 94.8% of xylenol orange and 98.8% of water–oil emulsion, and thus completely address the problem of energy consumption. This study further promotes the application of self-powered electrochemical systems in treating environmental pollution.