Solar-driven carbon-based fuels production is a promising way to store solar energy and alleviate the greenhouse effect. However, current approaches face a lot of challenges, such as poor selectivity, high overpotential, and the requirement of external electrical bias. In this study, based on the photoelectrochemical and bioelectrochemical technologies, we reported a novel self-biased hybrid solar-microbial device, which was capable of converting solar energy into methane without external electrical bias. Owing to the self-generated bias (~0.47 V) from the bioanode and the low overpotential (<50 mV) of the biocathode, the hybrid system demonstrated the conversion from carbon dioxide to methane with a high Faradaic efficiency up to 95.2% and retained a prolonged stability for 30 h using the solar energy as the sole energy input. Moreover, the hybrid system also achieved organic wastewater removal and azo dyes degradation. The development of the hybrid system for solar fuels production can provide a new way to address the increasing demand for renewable energy.

太阳能驱动的碳基燃料生产是一种有前途的存储太阳能和减轻温室效应的方法。但是，当前的方法面临许多挑战，例如选择性差，过电位高以及需要外部电偏置。在这项研究中，基于光电化学和生物电化学技术，我们报道了一种新型的自偏压混合太阳能-微生物装置，该装置能够将太阳能转换为甲烷而无外部电偏压。由于来自生物阳极的自生偏压（〜0.47 V）和生物阴极的低过电势（<50 mV），该混合系统显示了从二氧化碳到甲烷的转化，法拉第效率高达95.2％，并得以保留使用太阳能作为唯一的能量输入，可保持30小时的稳定性。此外，该混合系统还实现了有机废水的去除和偶氮染料的降解。用于太阳能燃料生产的混合动力系统的开发可以提供新的方式来解决对可再生能源日益增长的需求。