Hydrogen peroxide (H 2 O 2) has received increasing attention as an energy carrier. To achieve a sustainable energy society, photocatalytic H 2 O 2 splitting (H 2 O 2 (l) → H 2 (g) + O 2 (g); ΔG°= + 131 kJ mol −1) is a desirable reaction for on-site H 2 generation. However, this reaction has not been reported because conventional photocatalysis decomposes H 2 O 2 by disproportionation (H 2 O 2 (l) → H 2 O (l) + 1/2O 2 (g); ΔG°= −117 kJ mol −1) and by promoting H 2 O 2 reduction instead of H + reduction. Here we report the successful example of H 2 O 2 splitting. Visible light irradiation of a graphitic carbon nitride loaded with graphene quantum dots as co-catalysts (GQDs/g-C 3 N 4) in a H 2 O 2 solution containing phosphoric acid (H 3 PO 4) produces H 2. H 3 PO 4 associates with H 2 O 2 via hydrogen bonding, and this stabilization of H 2 O 2 suppresses its reduction, thus promoting H + reduction. The all-organic photosystem with H 3 PO 4 as a stabilizer may provide a basis of photocatalytic H 2 O 2 splitting.

We investigate the conditions for the validity of the "dipole approximation" in electron-energyloss spectroscopy (EELS) of atomic I( -shell excitations on an analytic model that takes account of the wave function of the ejected core electron, as well as that of the core state. We derive, for the first time, a closed-form expression for the limiting magnitude qd of the momentum-transfer vector, as a function of both the atomic number and the energy a of the ejected core electrons. We find that the value currently assumed, namely qq=Z, where Z is the effective nuclear charge, is only strictly valid in the limit of low energies of the ejected core electron. In fact qd decreases noticeably with increasing c.. Matrix elements with many different values of q contribute to a typical EELS signal, but the dominant ones lie close to the minimum value q;". The increase of q;"with c coupled with the decrease of qd with the same quantity makes it easier to satisfy the conditions for the dipole approximation in the near edge rather than the extended-fine-structure region of the energy-loss spectrum. Our analytic approach is well suited for extension to the cases of other absorption edges (e.g. , L, M, edges, etc.).

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A phenylurea derivative of a trident molecule has been prepared as a novel solvent extraction reagent for precious metal ions to compare the extraction ability of precious and base metals with the corresponding monopodal analogue in nitrate media. The phenylurea type of trident extraction reagent exhibited extractive selectivity for palladium over other precious and base metals in nitrate media. The extraction ability of the trident extraction reagent for palladium was superior to that of the monopodal analogue. The extraction mechanism of palladium with the trident extraction reagent was determined by slope analysis and from the peak shift for the FT-IR and 1 H-NMR spectra of the extraction reagent before and after metal loading.Stripping from the organic phase after forward extraction was carried out to separate palladium and silver.

The distribution constants of 4-benzoyl-3-phenyl-5-isoxazolone (HPBI) and deprotonated one (PBI) between hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([CCim][TfN]) and aqueous phases were determined, together with the acid-dissociation constant of HPBI. The solvent extraction of three selected lanthanoid ions (La, Eu, and Lu) with HPBI from aqueous nitrate phase into [CCim][TfN] has been investigated. Application of the ionic liquid as the extracting phase greatly enhanced the extraction performance of HPBI for lanthanoid ions compared with that in the chloroform system. A slope analysis was conducted in order to compare the results of the solution 4f-ion coordination chemistry in ionic and molecular media. The composition of the extracted species was established to be anionic tetrakis entities, Ln(PBI), for light, middle, and heavy lanthanoid ions in an ionic environment (Ln denotes lanthanoid ion). Nevertheless, the typical neutral chelate lanthanoid complexes of the type Ln(PBI) have been detected when the conventional molecular diluent chloroform was applied as an organic phase.