Thin film of mixed SnO2 and Sb2O3 on Cr18Ni12Ti high alloy steel (HAS) substrate (SnO2-Sb2O3/HAS) was fabricated by dip coating - pyrolysis method. The morphology and structure of the material surface was observed by scanning electron microscopy (SEM). The mechanical property was evaluated by using Vickers hardness test (HV test). The electrochemical properties of the formed film were investigated by open circuit potential measurement vs. time and potentiodynamic polarization curves in the NaCl solution. | Vietnam Journal of Science and Technology 55 (5B) (2017) 132-139 STUDY ON HIGHLY ALLOYED STEEL ANODE COATED BY MIXED METAL OXIDES SnO2 - Sb2O3 THIN FILM AND APPLICATION IN WASTEWATER TREATMENT Huynh Thu Suong*, Dang Trung Dung, Bui Thi Thanh Huyen, La The Vinh School of Chemical Engineering, Hanoi University of Science and Technology, 1 Dai Co Viet, Ha Noi * Email: huynhthusuong@ Received: 11 August 2017; Accepted for publication: 6 October 2017 ABSTRACT In this study, thin film of mixed SnO2 and Sb2O3 on Cr18Ni12Ti high alloy steel (HAS) substrate (SnO2-Sb2O3/HAS) was fabricated by dip coating - pyrolysis method. The morphology and structure of the material surface was observed by scanning electron microscopy (SEM). The mechanical property was evaluated by using Vickers hardness test (HV test). The electrochemical properties of the formed film were investigated by open circuit potential measurement vs. time and potentiodynamic polarization curves in the NaCl solution. The results indicate that the SnO2-Sb2O3/HAS electrode has high hardness and good electrochemical strength. The SnO2-Sb2O3/HAS electrode was used as an anode to remove Rhodamine B (RhB) - a color dye - from wastewater. The effect of electrolysis time on treatment efficiency for RhB is studied. The UV-Vis spectra and Total Organic Carbon (TOC) analysis shows that the RhB color dye are removed from wastewater via electrochemical oxidation process. Keywords: high alloy steel, SnO2-Sb2O3/HAS electrode, Rhodamine B, degradation, electrochemical oxidation. 1. INTRODUCTION Protection of the environment is one of the most challenging and pressing task for mankind due to industrial development. Now, the dyes industry is one of the most polluting industries in the world causing grave damage to the environment. Dyes are usually used in textile industries, paper industries, food technologies and also in agricultural research. Therefore, wastewater of these industries contain large amount of dye