A rapid two-step electroless deposition process to fabricate superhydrophobic coatings on steel substrates

The present study reports a simple, highly effective, and safe two-step electroless deposition process for rapidly fabricating superhydrophobic Ag coatings on steel substrates. The steel plates were first immersed in the 1?mol/L aqueous CuSO₄ solution for 20?s, and then immersed in the 0.03?mol/L aqueous AgNO₃ solution containing 1?wt% fluoroalkylsilane (FAS) for 2?min. The sample surfaces were characterized by energy-dispersive x-ray spectroscopy, Fourier transform infrared spectrophotometry (FTIR), x-ray diffraction, scanning electron microscopy, step profiler, and optical contact angle measurements. The results show that, after the two-step electroless deposition process, the Ag coatings composed of the binary micro/nanometer-scale rough structures containing the FAS molecules with a low surface energy are formed on the steel surfaces. The as-prepared Ag coatings exhibit a good superhydrophobicity with a 163.4?±?1.8° water contact angle and 1.5?±?0.5° rolling angle.