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[Display omitted] • Smartly designed metal/oxides heterojunction via a facile Ar-H 2 plasma reduction strategy. • The in-situ synthesized Ir/IrO 2 heterointerface possesses structural flexibility and abundant active sites. • Ir–IrO 2 /Ti@Ar–H 2 exhibits outstanding electrocatalytic activity and durability for both HER and OER. • Ir–IrO 2 /Ti@Ar–H 2 can used as an efficient and stable bifunctional catalyst for overall water splitting in acidic media. Iridium oxide (IrO 2) has been intensively investigated as an efficient and stable anode catalyst for the oxygen evolution reaction (OER) in water splitting system. However, the overall water splitting performance of IrO 2 is rarely studied because of its strong adsorption of hydrogen intermediates during the hydrogen evolution reaction (HER) process. Herein, a facile Ar/H 2 plasma reduction strategy is developed to activate the HER performance of self-supported IrO 2 by constructing a novel metal/oxide heterostructure. The in-situ synthesized Ir/IrO 2 composite possesses excellent electrical interconnection and abundant catalytic active sites. Meanwhile, dual active sites induced by the strong interface effect between metallic Ir and IrO 2 could optimize the adsorption energy and reaction path for both HER and OER. The optimized Ir–IrO 2 /Ti@Ar–H 2 exhibits remarkable activities with a small overpotential of 58 and 211 mV toward HER and OER, respectively. Besides, Ir–IrO 2 /Ti@Ar–H 2 ||Ir–IrO 2 /Ti@Ar–H 2 electrolyzer only requires an operational voltage of 1.48 V to afford a current density of 10 mA cm−2, much lower than that of commercial Pt/C||IrO 2 (1.61 V). [ABSTRACT FROM AUTHOR]

"Sputtering damage" arising from high-energy negative ions plays a pivotal role in shaping the characteristics of indium tin oxide (ITO) thin films deposited through direct-current magnetron sputtering (DCMS). To mitigate this issue, we employ DCMS with an external anode. The increment in anode bias V A from 0 to +60V effectively diminishes the average kinetic energy of negative ions such as O−, O2− and InO− by reducing the cathode voltage. Additionally, the flux of positive ions (e.g., Ar+, In+, Sn+, O+) increases and their ion energy distribution functions (IEDFs) exhibit supplementary peaks at plasma potentials. Both facilitate film crystallization, as evidenced by the structural transition from subgrain to grain formations. Heightened surface roughness markedly enhances optical transmittance. Due to a reduced oxygen sticking coefficient, films grown with higher V A values exhibit increased oxygen vacancies, which serve as the primary charge carriers for ITO films. Consequently, ITO films attain their lowest resistivity (7.81 × 10 − 4 Ω c m) and highest optical transmittance (78.71 %) at V A = +60V. This investigation underscores the significant influence of the external anode bias on both ion behavior and film growth, providing a viable approach to enhance the electrical and optical properties of ITO films. • Elevating the external anode bias mitigates high-energy negative ions while promoting the generation of positive ions. • Increased external anode bias enhances crystallinity, alters orientation, and boosts oxygen vacancies in ITO films. • Higher external anode bias yielded ITO films with reduced resistivity and improved visible light transmittance. • External anode can mitigate ion-induced "sputtering damage" without reducing deposition rate. [ABSTRACT FROM AUTHOR]