Bencheikh, YasminaAddad, AhmedCoffinier, YannickKumar, UmeshRoussel, PascalSzunerits, SabineHadjersi, ToufikAmin, Mohammed A.Abaidia, Seddik-El-HakBoukherroub, Rabah2021-10-102021-10-10202100134686https://www.sciencedirect.com/science/article/abs/pii/S0013468621014882https://doi.org/10.1016/j.electacta.2021.139198https://dspace.univ-boumerdes.dz/handle/123456789/7178In this paper, we fabricated silicon nanowire-TiO2 core-shell arrays in a two-step process. First, silicon nanowire arrays (SiNW) were prepared in HF/AgNO3 aqueous solution using metal-assisted chemical etching of bulk silicon. Then, atomic layer deposition (ALD) technique was applied to coat a 20 nm thin shell TiO2 film. The TiO2/SiNW substrates were afterward annealed at 400°C in hydrogen atmosphere for 4 h and tested as electrode materials for electrochemical micro-capacitors. The electrochemical features of the constructed H−TiO2/SiNW electrode were assessed in an aqueous 1 M Na2SO4 electrolyte solution and revealed that the specific capacitance increased six times compared to non-annealed TiO2/SiNW and 20-fold compared to a reference SiNW electrode under the same operating conditions. Importantly, H−TiO2/SiNW also displayed a high stability over 30,000 cycles at 0.1 mA cm−2 with an overall decrease of 19% of the initial capacitance. The hydrogen treatment increased the density of hydroxyl group and enhanced the carrier density on TiO2 surface improving the capacitive properties of H−TiO2/SiNWenSilicon nanowiresTiO2 thin filmHydrogenationMicro-capacitorHigh stabilityArticle