From materials to process: The role of binder and pressing-sintering conditions in optimizing the performance of substrate-free suboxide titanium electrode

Due to the unique structure, excellent physicochemical properties and very competitive cost of suboxide titanium materials, they have an enormous application potential in electrocatalytic oxidation. Suboxide titanium oxide electrode without substrate is a kind of ceramic state electrode, which is mainly prepared through powder granulation, high-pressure molding sheet and high-temperature sintering process. Because it is substrate-free, the preparation process is simple and has excellent performance. First of all, this paper explores the effects of different dosages of three binders, including liquid paraffin, chitosan, and polyvinyl butyral (PVB), on the performance of the electrodes during the granulation process. The optimal binder and its dosage of 2 wt% PVB were selected. Secondly, during the pressing and sintering process, orthogonal experiments were conducted to optimize the core factors, such as powder particle size, sintering temperature, and sintering time. The optimal preparation conditions of the material were obtained by evaluating the comprehensive degradation index: particle size of 80–100 mesh, sintering temperature of 1150 ℃, and sintering time of 180 min. Finally, this paper evaluated the optimized electrodes, which had excellent performance. The accelerated electrode lifetimes in unidirectional constant current and cyclic reverse polarity power supply modes were 180 h and 360 h, respectively. The optimized electrode was used as the anode for the electrocatalytic oxidative degradation of the acidic red G and the optimization of the degradation parameters, and the optimal parameter for the comprehensive degradation index was obtained as the following: current density of 25 mA·cm⁻², and the initial acidic red G concentration was 100 mg·L^-1.