Solar-powered water evaporation presents a promising solution to the escalating global freshwater crisis, offering a more sustainable alternative by exclusively utilizing solar energy. This study explores the design and operational parameters of an advanced solar evaporator for freshwater production, utilizing rod-based systems for solar-driven water evaporation. The system features alumina ceramic rods (ACRs) integrated with densely packed silica 1D nanosprings (NS), synthesized via the vapor-liquid-solid (VLS) process. To optimize solar energy absorption and minimize the water contact angle, a graphene layer, derived from the University of Idaho Thermolyzed Asphalt Reaction (GUITAR), is deposited onto the ACR surface using atmospheric pressure chemical vapor deposition (APCVD). Through optimization, it was determined that the optimal nanospring (NS) thickness enhances the wicking mechanism along the rod surfaces by facilitating capillary action across the nanospring structures. The integration of one-dimensional nanosprings (1D NS) onto the ACR surface leads to a notable 16.7% increase in the evaporation rate when compared to the ACR equipped solely with a GUITAR structure. Under the optimized design and operational conditions, the system achieves an impressive evaporation rate of 5.8 kg m⁻² h⁻¹ with the fresh water. The system demonstrated a high evaporation rate of 3.51 kg m⁻² h⁻¹ in a 0.1 wt% salt solution under 1 sun irradiation. To evaluate its practical applicability in solar desalination, a salt rejection experiment was conducted, revealing a 98.3% reduction in Na⁺ ion concentration, confirming the system's strong desalination performance. This efficiency highlights the crucial role that nanostructural design plays in enhancing solar evaporation systems. The findings show the importance of optimizing nanostructure dimensions to maximize heat and mass transfer, improving overall evaporation performance and demonstrating the viability of such systems.
