Process optimisation for n-type Bi₂Te₃ films electrodeposited on flexible recycled carbon fibre using response surface methodology

Electrodeposition method was used to synthesise n-type bismuth telluride (Bi₂Te₃) films on recycled carbon fibre under different deposition conditions. D-optimal model under response surface methodology was used to design the experiment and optimise the following deposition parameters: deposition potential (V), deposition time (h), deposition temperature (°C) and electrolyte composition (molar concentration). The effects of electrodeposition parameters were evaluated within the limits of deposition potential (−0.10 to −0.60 V), deposition time (0.5–3 h), deposition temperature (25–60 °C) and electrolyte composition (0.2, 0.4 and 0.6 of Bi/(Bi + Te)). The optimum conditions for the electrodeposition parameters with the least amount of chemicals, time and energy consumption were −0.10 V, 0.5 h, 25 °C and 0.240 Bi/(Bi + Te), respectively, for deposition potential, deposition time, deposition temperature and electrolyte composition. Moreover, the validation of predicted values shows good agreement with experimental results with 1.45% deviation.