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Electrochemical water splitting produces clean hydrogen fuel as one of the pivotal alternative energies to fossil fuels in the near future. However, the anodic oxygen evolution reaction (OER) is a significant bottleneck that curtails large-scale applications of electrochemical water splitting technology, owing to its sluggish reaction kinetics. In the past few decades, various methods have been proposed to improve the OER kinetics. Among them, doping is a simple and efficient method to mold the OER kinetics of a catalyst by incorporating different or hetero atoms into the host lattice. These efforts are vital to design highly efficient OER catalysts for real-world applications. However, the OER mechanism of a doped catalyst varies, depending on the host lattice and the dopant. This review highlights different doping strategies and associated OER mechanisms of state-of-the-art catalysts, including oxides (noble metal oxides, perovskite oxides, spinel oxides, hydroxides and others), non-oxides (metal sulfides, metal selenides, metal phosphides, metal nitrides and metal carbides), and carbon-based catalysts (graphene, carbon nanotubes and others). Fundamental understanding of the doping effects on the OER from combined experimental and theoretical research provides guidelines for designing efficient catalysts.

Glucose biosensors are widely used for clinical, industrial, and environmental applications. Nonenzymatic electrochemical glucose biosensors based on metal oxides with a perovskite structure have exhibited high sensitivity, excellent stability, and cost efficiency. In this work, porous La–Sr–Co–Ni–O (LSCNO) nanofibers, with an ABO 3 -type perovskite structure, were prepared through optimizing the A-site and B-site elements by electrospinning, followed with calcination at 700 °C for 5 h. Characterized by scanning and transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, fabricated nanofibers were confirmed to be porous and nanosized polycrystalline grains with high crystallinity. A novel La 0.75 Sr 0.25 Co 0.5 Ni 0.5 O 3 -based nonenzymatic electrochemical biosensor was developed, which is sensitive to glucose because of an electrochemically catalytic mechanism, a mediated electron transfer involving Ni( ii )/Ni( iii ) or Co( ii )/Co( iii ), accompanying with gluconic acid complexation. The glucose biosensor presented a linear response in the range of 0.1–1.0 mM with a calibration sensitivity of 924 ± 28 μA mM −1 , a proportion of the variance of 0.9926, and a lower limit of detection of 0.083 mM, respectively, demonstrating an outstanding analytical performance. The biosensor showed no response to the most widely usedmore »anionic surfactant, sodium dodecyl sulfate, and low sensitivity to other biomolecules, such as fructose, lactose, galactose, mannose, dopamine, and ascorbic acid. A urine sample was tested by this novel nonenzymatic electrochemical biosensor by standard addition method, suggesting a potential application for clinical test.« less

Scintillator materials convert high-energy radiation into photons in the ultraviolet to visible light region for radiation detection. In this review, advances in X-ray emission dynamics of inorganic scintillators are presented, including inorganic halides (alkali-metal halides, alkaline-earth halides, rare-earth halides, oxy-halides, rare-earth oxyorthosilicates, halide perovskites), oxides (binary oxides, complex oxides, post-transition metal oxides), sulfides, rare-earth doped scintillators, and organic-inorganic hybrid scintillators. The origin of scintillation is strongly correlated to the host material and dopants. Current models are presented describing the scintillation decay lifetime of inorganic materials, with the emphasis on the short-lived scintillation decay component. The whole charge generation and the de-excitation process are analyzed in general, and an essential role of the decay kinetics is the de-excitation process. We highlighted three decay mechanisms in cross luminescence emission, exitonic emission, and dopant-activated emission, respectively. Factors regulating the origin of different luminescence centers controlling the decay process are discussed.