Optimization of 3D-Printed Solar Evaporators for Enhanced Interfacial Solar Steam Generation and Beyond: Investigating Surface Modifications and Nanocomposite Coatings

Abstract

The present work investigates the influence of variations in top evaporative surface angle of the 3D-printed solar evaporators in interfacial solar steam generation (ISSG). In this regard, different convex surface modifications such as 0˚, 15˚, 30˚ and 45˚ inclination are fabricated and covered with carbon cloth (CX-0, CX-15, CX-30 and CX-45). Among all, CX-45 evaporator exhibits better ISSG performance and hence, CX-45 evaporator is alone coated with as-synthesized tantalum oxide/potassium tantalate nanocomposite (CX-45/NC) and used to study the enhancement in ISSG. At 1 kW/m2 solar illumination, mass loss (ML), evaporation flux (EF) and efficiency (EY) are measured and found to be 2.5 g, 4.366 kg/m2h and 104.95% respectively for 60 min duration. Furthermore, the outdoor performance (∼656.791 W/m2 for 8 h) of the above evaporator exhibits better ML, EF and EY of about7.5 g, 1.637 kg/m2h and 59.99% respectively. We propose that: (i) increasing the top evaporative surface angle of the 3D evaporator enhances the surface area, facilitating the accumulation of a greater amount of water molecules (ii) the low thermal conductivity of the 3D-printed material prevents excessive heat flow to the bulk water (iii) the presence of water-absorbing groups within the carbon cloth accelerates the rate of water absorption (iv) applying a nanocomposite coating onto the carbon cloth surface enhances its ability to trap light energy effectively (v) enhanced surface roughness of the 3D-printed evaporator minimizes heat losses through mechanisms such as scattering and reflection. Moreover, the developed 3D-printed evaporator gives a sustainable solution for the purification of dye molecules and oil-water separation, as evident from this study.