We briefly reviewed and summarized the experimental study on β-delayed proton decays published by our group over the last 8 years, namely the experimental observation of β-delayed proton decays of nine new nuclides in the rare-earth region near the proton drip line and five nuclides in the mass 90 region with N ∼ Z by utilizing the p-γ coincidence technique in combination with a He-jet tape transport system. In addition, important technical details of the experiments were provided. The experimental results were compared to the theoretical predictions of some nuclear models, resulting in the following conclusions. (1) The experimental half-lives for 85 Mo, 92 Rh, as well as the predicted "waiting point" nuclei 89 Ru and 93 Pd were 5-10 times longer than the macroscopic-microscopic model predictions of Möller et al. [At. Data Nucl. Data Tables 66, 131 (1997)]. These data considerably influenced the predictions of the mass abundances of the nuclides produced in the rp process.(2) The experimental assignments of spin and parity for the drip-line nuclei 142 Ho and 128 Pm could not be well predicted by any of the nuclear models. Nevertheless, the configuration-constrained nuclear potential-energy surfaces calculated by means of a Woods-Saxon-Strutinsky method could reproduce the assignments. (3) The ALICE code overestimated by one or two orders of magnitude the production-reaction cross sections of the nine studied rare-earth nuclei, while the HIVAP code overestimated them by approximately one order of magnitude.

Photocatalytic ozonation of wastewater pollutants by sunlight is a highly attractive technology close to real application. Understanding this process on the atomic scale and under realistic working conditions is challenging but vital for the rational design of catalysts and photocatalytic decontamination systems. Here we study two highly active C 3 N 4 photocatalysts (bulk C 3 N 4 and a nanosheet-structured C 3 N 4 ) under simultaneous visible-light irradiation and O 3 bubbling in water by in situ EPR spectroscopy coupled with an online spintrapping technique. The photoexcitation of electrons to the conduction band (CB-e − ), their further trapping by dissolved O 2 and O 3 , and the evolution of reactive oxygen species (ROS) have been semiquantitatively visualized. A dual role of O 3 in boosting the CB-e − to • OH conversion is confirmed: (i) an inlet 2.1 mol % O 3 /O 2 gas mixture can trap about 2−3 times more CB-e − upon aqueous C 3 N 4 suspension than pure O 2 and further produce • OH by a robust • O 3 − -mediated one-electron-reduction pathway (O 3 → • O 3 − → HO 3 • → • OH); (ii) O 3 can readily take CB-e − back from • O 2 − to form • O 3 − , thus blocking the inefficient H 2 O 2 -mediated three-electron-reduction route (O 2 → • O 2 − → HO 2 • → H 2 O 2 → • OH) but further strengthening the • O 3 − -mediated pathway. In the presence of 2.1 mol % O 3 /O 2 , the • OH yield increases by 17 and 5 times, and consequently, the mineralization rate constant of oxalic acid increases by 84 and 41 times over bulk C 3 N 4 and NS C 3 N 4 , respectively. This work presents an attractive opportunity to boost the yield of ROS species ( • OH) for water purification by visible-light-driven photocatalysis and provides a powerful tool to monitor complex photocatalytic reactions under practical conditions.

Nanocarbons have been demonstrated as promising environmentally benign catalysts for advanced oxidation processes (AOPs) upgrading metal-based materials. In this study, reduced graphene oxide (rGO) with a low level of structural defects was synthesized via a scalable method for catalytic ozonation of p-hydroxylbenzoic acid (PHBA). Metal-free rGO materials were found to exhibit a superior activity in activating ozone for catalytic oxidation of organic phenolics. The electron-rich carbonyl groups were identified as the active sites for the catalytic reaction. Electron spin resonance (ESR) and radical competition tests revealed that superoxide radical ((•)O2(-)) and singlet oxygen ((1)O2) were the reactive oxygen species (ROS) for PHBA degradation. The intermediates and the degradation pathways were illustrated from mass spectroscopy. It was interesting to observe that addition of NaCl could enhance both ozonation and catalytic ozonation efficiencies and make ·O2(-) as the dominant ROS. Stability of the catalysts was also evaluated by the successive tests. Loss of specific surface area and changes in the surface chemistry were suggested to be responsible for catalyst deactivation.

A 3D configuration of high-quality graphene sheets and a polyoxometalate [H7P8W48O184]33− showing excellent hydrogen evolution activity at extremely low overpotential.

Highlights  Highly active rGO materials were synthesized from waste anode graphite.  Adsorption of ozone on graphene structure was simulated by DFT calculations.  Defects within graphene structure were active for catalytic ozonation.  A pollutant-structure-dependent behavior of dominant ROS was discovered.  Reaction mechanisms differed for phenolic and aliphatic pollutants.

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