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Exploring efficient, low cost and stable electrocatalysts working at large current densities is crucial for upgrading the current industrial electrochemical water splitting. Herein, a novel FeS2/Fe–Ni3S2 heterostructure was successfully prepared via a simple one-step in situ hydrothermal vulcanization using F− regulation engineering. The FeS2/Fe–Ni3S2 heterostructure array exhibits low overpotentials for both the OER (180 mV @ 10 mA cm−2 and 300 mV @ 1 A cm−2) and the HER (105 mV @ 10 mA cm−2 and 344 mV @ 1 A cm−2) with high stability operating at 1 A cm−2 for 1000 h. In addition, the water-splitting system only needs 1.5 V to reach 10 mA cm−2 and shows prolonged stability of more than 1200 h at 1 A cm−2. The DFT calculations show that the electrons redistribute at the interface and favor the chemisorption of hydrogen and oxygen-containing intermediates. This work highlights a novel, low cost and practical electrode for industrial electrochemical water splitting. [ABSTRACT FROM AUTHOR]

High-entropy oxide (HEO) nanoparticles have been regarded as a promising catalytic material system for oxygen evolution reaction in recent years. However, their traditional physical and chemical synthesis remains challenges due to the limitation of fabricating controllable small size HEO nanoparticles. Herein, a general and novel method of low-energy-recoil ion implantation and subsequent annealing is successfully developed to synthesize high-entropy oxide nanoparticles catalysts. By controlling the fluence of irradiation Ar+ ions, the size and the load of HEO nanoparticles can be accurately controlled. The obtained (FeCoNiCrAl)O HEO nanoparticles exhibit an overpotential of 295 mV at 10 mA cm−2, a small Tafel slope of 39 mV dec−1 and good stability in 1 M KOH, which is much better than the properties of binary and medium entropy oxide counterparts prepared by the same method, showing the good application prospect of low-energy-recoil ion implantation in the preparation of complicated multi-element-metal oxide nanoparticles. [ABSTRACT FROM AUTHOR]

Exploring earth‐abundant, highly effective, and stable electrocatalysts for overall water and urea electrolysis is urgent and essential for developing hydrogen energy technology. Herein, a simple self‐derivation method is used to fabricate a Fe‐doped Ni3S2 electrode. The electrode exhibits an impressive trifunctional catalyst, with low overpotentials of 290, 198, and 254 mV at 100 mA cm−2 for the oxygen evolution reaction (OER), urea oxidation reaction (UOR), and hydrogen evolution reaction (HER). The durability is higher than 3500 h (146 days) at 100 mA cm−2 for the OER without obvious change. In situ Raman spectra reveal the incorporation of Fe inhibited S dissolution and facilitates the catalyst reconstruction. The density functional theory calculations indicate that the doping of Fe optimizes the adsorption of the rate‐determining step and the d‐band center is closer to the Fermi level, which accelerates the OER process. The two‐electrode electrolyzer needs the cell voltages of only 1.76 and 1.57 V to achieve a current density of 100 mA cm−2 and remarkable durability for more than 500 h at 100 and 500 mA cm−2 for overall water and urea splitting. This work holds great promise for industrial water and urea splitting applications. [ABSTRACT FROM AUTHOR]

Utilization of visible light is of crucial importance for exploiting efficient semiconductor catalysts for solar water splitting. In this study, an advanced ion implantation method was utilized to dope Cu ions into ZnO nanorod arrays for photoelectrochemical water splitting in visible light. X-ray diffraction (XRD) and X-ray photo-electron spectroscopy (XPS) results revealed that Cu together with a small amount of Cu were highly dispersed within the ZnO nanorod arrays. The Cu ion doped ZnO nanorod arrays displayed extended optical absorption and enhanced photoelectrochemical performance under visible light illumination ( λ > 420 nm). A considerable photocurrent density of 18 μA/cm at 0.8 V (vs. a saturated calomel electrode) was achieved, which was about 11 times higher than that of undoped ZnO nanorod arrays. This study proposes that ion implantation could be an effective approach for developing novel visible-light-driven photocatalytic materials for water splitting. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Developing high-performance tungsten plasma-facing materials for fusion reactors is an urgent task. In this paper, novel nanochannel structural W films prepared by magnetron sputtering deposition were irradiated using a high-power pulsed electron beam or ion beam to study their edge-localized modes, such as transient thermal shock resistance. Under electron beam irradiation, a 1 μm thick nanochannel W film with 150 watt power showed a higher absorbed power density related cracking threshold (0.28–0.43 GW/m2) than the commercial bulk W (0.16–0.28 GW/m2) at room temperature. With ion beam irradiation with an energy density of 1 J/cm2 for different pulses, the bulk W displayed many large cracks with the increase of pulse number, while only micro-crack networks with a width of tens of nanometers were found in the nanochannel W film. For the mechanism of the high resistance of nanochannel W films to transient thermal shock, a residual stress analysis was made by Grazing-incidence X-ray diffraction (GIXRD), and the results showed that the irradiated nanochannel W films had a much lower stress than that of the irradiated bulk W, which indicates that the nanochannel structure can release more stress, due to its special nanochannel structure and ability for the annihilation of irradiation induced defects. [ABSTRACT FROM AUTHOR]

Developing high-radiation-tolerant inert matrix fuel (IMF) with a long lifetime is important for advanced fission nuclear systems. In this work, we combined zirconia (ZrO2) with magnesia (MgO) to form ultrafine-grained ZrO2–MgO composite ceramics. On the one hand, the formation of phase interfaces can stabilize the structure of ZrO2 as well as inhibiting excessive coarsening of grains. On the other hand, the grain refinement of the composite ceramics can increase the defect sinks. Two kinds of composite ceramics with different grain sizes were prepared by spark plasma sintering (SPS), and their radiation damage behaviors were evaluated by helium (He) and xenon (Xe) ion irradiation. It was found that these dual-phase composite ceramics had better radiation tolerance than the pure yttria-stabilized ZrO2 (YSZ) and MgO. Regarding He+ ion irradiation with low displacement damage, the ZrO2–MgO composite ceramic with smaller grain size had a better ability to manage He bubbles than the composite ceramic with larger grain size. However, the ZrO2–MgO composite ceramic with a larger grain size could withstand higher displacement damage in the phase transformation under heavy ion irradiation. Therefore, the balance in managing He bubbles and phase stability should be considered in choosing suitable grain sizes. [ABSTRACT FROM AUTHOR]

Defect engineering is an important method for enhancing photocatalytic performance. In article no. 1800298, Zhaowu Wang, Feng Ren, and co‐workers successfully design and prepare a defective g‐C3N4 photocatalyst via ion irradiation technology, achieving simultaneous introduction of C‐ and N‐ vacancies and the control of vacancy concentration, thus realizing a remarkable improvement in photocatalytic hydrogen production performance. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g‐C3N4) is reported to be a promising metal‐free semiconductor for photocatalytic water splitting. However, the performance of g‐C3N4 is substantially limited by its insufficient visible‐light absorption and low photogenerated charge carrier separation efficiency. In this work, an innovative method (ion irradiation) to efficiently introduce both defined C‐ and N‐vacancies (VC and VN) simultaneously into g‐C3N4 nanosheets are explored. Unlike traditional chemical methods, by controlling He+ ion fluence, tunable vacancy concentrations are able to be obtained in g‐C3N4. Defect‐engineered g‐C3N4 shows highly improved performance under optimized conditions, the defective g‐C3N4 exhibits a significantly higher (2.7‐fold) hydrogen evolution rate of 1271 µmol g−1 h−1 than that of the g‐C3N4 nanosheets under visible light (λ > 420 nm) illumination. Meanwhile, the defective g‐C3N4 exhibits a significantly enhanced (threefold) photocurrent density as photoanodes for photoelectrochemical (PEC) water splitting. Further characterizations show that the enhanced visible light absorption and an extended charge carrier lifetime, can be ascribed to the presence of C‐ and N‐ vacancies. These experimental results are in line with density functional theory (DFT) calculations. Therefore, the present work shows that defect‐engineering on g‐C3N4 using ion irradiation technique, is an effective, controllable, and defined approach to improve the photocatalytic and PEC water splitting performance of g‐C3N4. Defective g‐C3N4 photocatalysts are successfully prepared by ion irradiation technology, achieving simultaneous introduction of C– and N– vacancies and the control of vacancy concentration. The C– and N– vacancies help to enhance the absorption of visible light and the separation efficiency of photogenerated carriers, respectively, thus realizing the remarkable improvement of photocatalytic hydrogen production performance. [ABSTRACT FROM AUTHOR]

Solution-based ZnO nanorod arrays (NRAs) were modified with controlled N doping by an advanced ion implantation method, and were subsequently utilized as photoanodes for photoelectrochemical (PEC) water splitting under visible light irradiation. A gradient distribution of N dopants along the vertical direction of ZnO nanorods was realized. N doped ZnO NRAs displayed a markedly enhanced visible-light-driven PEC photocurrent density of ~160 μA/cm2 at 1.1 V vs. saturated calomel electrode (SCE), which was about 2 orders of magnitude higher than pristine ZnO NRAs. The gradiently distributed N dopants not only extended the optical absorption edges to visible light region, but also introduced terraced band structure. As a consequence, N gradient-doped ZnO NRAs can not only utilize the visible light irradiation but also efficiently drive photo-induced electron and hole transfer via the terraced band structure. The superior potential of ion implantation technique for creating gradient dopants distribution in host semiconductors will provide novel insights into doped photoelectrode materials for solar water splitting. [ABSTRACT FROM AUTHOR]

We report a simple and novel method to fabricate high quality titanium dioxide (TiO2) nanofilms on soda lime glass by a solid phase growth process of Ti implantation and subsequent annealling at 500 °C in oxygen atmosphere. The formation of the TiO2 nanofilms is resulted from the slow out-diffusion of implanted Ti ions from the substrates and being oxidized at the surfaces. The formed TiO2 nanofilms show superhydrophilicity and good antibacterial property with good adhesion to substrate and stability, suggesting that the TiO2 nanofilms formed by this method have great potential applications such as antibacterial, anti-fog and self-cleaning transparent glass. [ABSTRACT FROM AUTHOR]