Abstract Interfacial solar steam generation is emerging as a promising high-efficiency strategy to produce clean water by harvesting and converting clean solar energy to the localized heat. It is highly desirable to introduce robust materials that are able to bear the extreme conditions for advanced applications of solar steam generation. Here, we demonstrate an all-in-one interfacial solar evaporator made from poly(p-phenylene benzobisoxazole) nanofiber (PBONF)/graphene oxide (GO) and PBONF/reduced graphene oxide (RGO) composite aerogels with high porosity, robust mechanical properties, and excellent thermal insulation performance. The evaporators of PBONF/RGO composite aerogel show fast and durable solar-vapor conversion with a high efficiency of 98.4 % under unconcentrated one sun irradiation. The PBONFs not only reinforce the mechanical properties of composite aerogels, but also affords them great potential applications in wastewater purification in some extreme environment, for instance, aerospace.