Facile SILAR preparation of Fe(OH)3/Ag/TiO2 nanotube arrays ternary hybrid for supercapacitor negative electrode

Abstract The ternary hybrid composite electrode of Fe(OH)3/Ag/TNTA (where TNTA stands for TiO2 nanotube arrays) was prepared by a simple successive ionic layer adsorption and reaction method. The effects of calcination temperature of Ag/TNTA, drying temperature of Fe(OH)3/Ag/TNTA, and deposition amount of Ag and Fe(OH)3 on the supercapacitor performance of the composite electrode were investigated, and the related reasons were discussed in detail. The results show that Ag modification can obviously improve the performance of Fe(OH)3/TNTA composite electrode. Both the calcination temperature of Ag/TNTA and the deposition amount of Ag affect the particle size of Ag and the reaction resistance of the electrode. The deposition amount of Fe(OH)3 also has influence on the reaction resistance of the electrode. Under the optimized conditions, the capacitance value of the Fe(OH)3/Ag/TNTA composite electrode is as high as 84.67 mF cm−2@5 mV s−1（596.30 F g−1@5 mV s−1）, and the electrode has high rate performance and good cycle stability. The asymmetric supercapacitor assembled with Fe(OH)3/Ag/TNTA as the negative electrode and activated carbon as the positive electrode can store energy stably under the potential window of 0–1.5 V. When the power density is 2.77 kW kg−1 (50 mW cm−3), the energy density can reach 18.34 Wh kg−1 (0.33 mWh cm−3).