Advancing solar steam generation for seawater desalination: Global research trends, photothermal materials, structural innovations, and future directions

The growing global demand for clean water and sustainable energy has accelerated the development of solar-thermal desalination (STD) as an environmentally friendly solution. Solar steam generation (SSG) improves the efficiency of STD by concentrating solar energy conversion into heat at the water–air interface, thereby minimizing heat loss and accelerating the evaporation rate. This study combines bibliometric mapping and systematic review to provide a comprehensive perspective on the development of SSG for desalination. A total of 402 Scopus-indexed articles up to March 2025 were analyzed. Bibliometric analysis shows rapid growth in publications since 2016, with China dominating output and citation impact, while international collaboration remains uneven. Keyword evolution confirms a paradigm shift from carbon-based absorbers toward MXene-based innovations and structural design optimization. A further systematic review identified three key factors determining optimal SSG performance: (i) material class, where MXene achieves near-theoretical efficiency but is prone to oxidation, carbon materials offer stability and low cost despite weaker photothermal conversion, while metal materials provide strong plasmonic heating but are constrained by cost and scalability; (ii) interface architecture, where multilayer and aerogel designs enhance heat localization, water transport, and salt rejection, with evaporation rates exceeding 2.5–4.5 kg·m⁻²·h⁻¹ under one sun irradiation; and (iii) operational stability, which remains limited by oxidation, salt fouling, and degradation over long-term cycles. Based on these findings, this study proposes a roadmap for future research that prioritizes the development of oxidation-resistant MXene composites, rational interface architecture, advanced antifouling strategies, low-cost biomass substrates, standardized field evaluation protocols, and integration with hybrid renewable energy systems. Overall, these findings not only consolidate previously fragmented knowledge but also provide strategic guidance to drive SSG technology development toward higher efficiency, robust operational durability, and real scalability in solar-powered desalination applications.