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The development of smart and sustainable photocatalysts is in high priority for the synthesis of H2O2because the global demand for H2O2is sharply rising. Currently, the global market share for H2O2is around 4 billion US$ and is expected to grow by about 5.2 billion US$ by 2026. Traditional synthesis of H2O2via the anthraquinone method is associated with the generation of substantial chemical waste as well as the requirement of a high energy input. In this respect, the oxidative transformation of pure water is a sustainable solution to meet the global demand. In fact, several photocatalysts have been developed to achieve this chemistry. However, 97% of the water on our planet is seawater, and it contains 3.0–5.0% of salts. The presence of salts in water deactivates the existing photocatalysts, and therefore, the existing photocatalysts have rarely shown reactivity toward seawater. Considering this, a sustainable heterogeneous photocatalyst, derived from hydrolysis lignin, has been developed, showing an excellent reactivity toward generating H2O2directly from seawater under air. In fact, in the presence of this catalyst, we have been able to achieve 4085 μM of H2O2. Expediently, the catalyst has shown longer durability and can be recycled more than five times to generate H2O2from seawater. Finally, full characterizations of this smart photocatalyst and a detailed mechanism have been proposed on the basis of the experimental evidence and multiscale/level calculations.

14N magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of diamagnetic LaTiO2N perovskite oxynitride and its paramagnetic counterpart CeTiO2N are presented. The latter, to the best of our knowledge, constitutes the first high-resolution 14N MAS NMR spectrum collected from a paramagnetic solid material. The unpaired 4f-electrons in CeTiO2N do not induce a paramagnetic 14N NMR shift. This is remarkable given the direct Ce−N contacts in the structure for which ab initiocalculations predict substantial Ce→14N contact shift interaction. The same effect is revealed with 14N MAS NMR for SrWO2N (unpaired 5d-electrons).

Mixed-anion inorganic compounds offer diverse functionalities as a function of the different physicochemical characteristics of the secondary anion. The quaternary metal oxynitrides, which originate from substituting oxygen anions (O2–) in a parent oxide by nitrogen (N3–), are encouraging candidates for photoelectrochemical (PEC) water splitting because of their suitable and adjustable narrow band gap and relative negative conduction band (CB) edge. Given the known photochemical activity of LaTiO2N, we investigated the paramagnetic counterpart NdTiO2+xN1–x. The electronic structure was explored both experimentally and theoretically at the density functional theory (DFT) level. A band gap (Eg) of 2.17 eV was determined by means of ultraviolet–visible (UV–vis) spectroscopy, and a relative negative flat band potential of −0.33 V vs reversible hydrogen electrode (RHE) was proposed via Mott–Schottky measurements. 14N solid state nuclear magnetic resonance (NMR) signals from NdTiO2+xN1–xcould not be detected, which indicates that NdTiO2+xN1–xis berthollide, in contrast to other structurally related metal oxynitrides. Although the bare particle-based photoanode did not exhibit a noticeable photocurrent, Nb2O5and CoOxoverlayers were deposited to extract holes and activate NdTiO2+xN1–x. Multiple electrochemical methods were employed to understand the key features required for this metal oxynitride to fabricate photoanodes.

Bismuth(III) oxide-carbodiimide (Bi2O2NCN) has been recently discovered as a novel mixed-anion semiconductor, which is structurally related to bismuth oxides and oxysulfides. Given the structural versatility of these layered structures, we investigated the unexplored photochemical properties of the target compound for photoelectrochemical (PEC) water oxidation. Although Bi2O2NCN does not generate a noticeable photocurrent as a single photoabsorber, the fabrication of heterojunctions with the WO3thin film electrode shows an upsurge of current density from 0.9 to 1.1 mA cm–2at 1.23 V vs reversible hydrogen electrode (RHE) under 1 sun (AM 1.5G) illumination in phosphate electrolyte (pH 7.0). Mechanistic analysis and structural analysis using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and scanning transmission electron microscopy energy-dispersive X-ray spectroscopy (STEM EDX) indicate that Bi2O2NCN transforms during operating conditions in situto a core–shell structure Bi2O2NCN/BiPO4. When compared to WO3/BiPO4, the in situelectrolyte-activated WO3/Bi2O2NCN photoanode shows a higher photocurrent density due to superior charge separation across the oxide/oxide-carbodiimide interface layer. Changing the electrolyte from phosphate to sulfate results in a lower photocurrent and shows that the electrolyte determines the surface chemistry and mediates the PEC activity of the metal oxide-carbodiimide. A similar trend could be observed for CuWO4thin film photoanodes. These results show the potential of metal oxide-carbodiimides as relatively novel representatives of mixed-anion compounds and shed light on the importance of the control over the surface chemistry to enable the in situactivation.

Spherical mesoporous carbon (with a particle size in the range of 40–75 μm) was synthesized by nanoreplication of a hard silica template using sucrose as the carbon precursor. The mesoporous carbon with BET surface areas higher than 1200 m2/g was doped with N by a treatment in an aqueous solution of nitric acid and/or in a flow of gaseous ammonia. The highest N content (3.2 wt % of N in bulk) was obtained when both modification methods were combined. Complementary physicochemical characterization techniques, including scanning electron microscopy (SEM), low-temperature N2adsorption, powder X-ray diffraction (XRD), and Raman spectroscopy revealed the morphology, structure, and textural properties of the synthesized N-loaded carbon materials. For the identification of the detailed chemical structure on the surface of the carbons, 1H, 13C, and 15N solid-state nuclear magnetic resonance (NMR) measurements were performed, and the data were supported by chemical shift calculations with accurate quantum chemistry methods and X-ray photoelectron spectroscopic (XPS) analyses. All NMR experiments were performed at natural isotope abundance. The verified experimental data clearly showed that after the introduction of the N-containing moieties by the combined methods of treatment, a high concentration of pyridinic N at the edge, and pyrrolic N being external to the edge, was achieved for the mesoporous carbon. The distributed N surface species promoted the catalytic activity in the oxidative dehydrogenation of ethylbenzene to styrene but did not significantly influence the efficiency of the carbon materials in the electrochemical reduction of nitrate ions.

Conjugated polymers are emerging as alternatives to inorganic semiconductors for the photoelectrochemical water splitting. Herein, semi-transparent poly(4-alkylthiazole) layers with different trialkylsilyloxymethyl (R3SiOCH2−) side chains (PTzTNB, R = n-butyl; PTzTHX, R = n-hexyl) are applied to functionalize NiO thin films to build hybrid photocathodes. The hybrid interface allows for the effective spatial separation of the photoexcited carriers. Specifically, the PTzTHX-deposited composite photocathode increases the photocurrent density 6- and 2-fold at 0 V versus the reversible hydrogen electrode in comparison to the pristine NiO and PTzTHX photocathodes, respectively. This is also reflected in the substantial anodic shift of onset potential under simulated Air Mass 1.5 Global illumination, owing to the prolonged lifetime, augmented density, and alleviated recombination of photogenerated electrons. Additionally, coupling the inorganic and organic components also enhances the photoabsorption and amends the stability of the photocathode-driven system. This work demonstrates the feasibility of poly(4-alkylthiazole)s as an effective alternative to known inorganic semiconductor materials. We highlight the interface alignment for polymer-based photoelectrodes.

In this work, we have fabricated an aryl amino-substituted graphitic carbon nitride (g-C3N4) catalyst with atomically dispersed Mn capable of generating hydrogen peroxide (H2O2) directly from seawater. This new catalyst exhibited excellent reactivity, obtaining up to 2230 μM H2O2in 7 h from alkaline water and up to 1800 μM from seawater under identical conditions. More importantly, the catalyst was quickly recovered for subsequent reuse without appreciable loss in performance. Interestingly, unlike the usual two-electron oxygen reduction reaction pathway, the generation of H2O2was through a less common two-electron water oxidation reaction (WOR) process in which both the direct and indirect WOR processes occurred; namely, photoinduced h+directly oxidized H2O to H2O2via a one-step 2e–WOR, and photoinduced h+first oxidized a hydroxide (OH–) ion to generate a hydroxy radical (•OH), and H2O2was formed indirectly by the combination of two •OH. We have characterized the material, at the catalytic sites, at the atomic level using electron paramagnetic resonance, X-ray absorption near edge structure, extended X-ray absorption fine structure, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, magic-angle spinning solid-state NMR spectroscopy, and multiscale molecular modeling, combining classical reactive molecular dynamics simulations and quantum chemistry calculations.

Semi transparent three-dimensional macroporous (3DM) photoanodes based on quaternary oxynitrides have the potential to simultaneously realize superior light harvesting and efficient charge transfer in a tandem photoelectrochemical (PEC) cell. A 3DM CaTaO2N photoanode was prepared for the first time on a GaN/Al2O3substrate viaa chemical route, and it exhibits a high transmittance of >60% in the wide solar spectrum and a photoresponse onset at −0.3 V versusthe reversible hydrogen electrode (VRHE) under simulated solar illumination. In particular, a plateau photocurrent density of 0.21 mA cm–2was achieved at a low potential of 0.4 VRHE, which was 1.6-fold and more than 50-fold higher than a two-dimensional macroporous (2DM) CaTaO2N/GaN/Al2O3photoanode and a conventional particle-based CaTaO2N/GaN/Al2O3photoanode, respectively. The bicontinuous, interconnected pore structure within this 3DM film can improve charge carrier separation and collection by reducing the average diffusion distance for minority carriers toward the electrolyte. Optical measurements and simulations verified the enhanced sunlight harvesting in the 3DM photoanode, which was ascribed to the concentrated distribution of the electric field and multiple scattering. This study provides guidance for future synthesis of highly efficient semitransparent 3DM quaternary oxynitride-based photoanodes for a tandem PEC device.

The retrospective analysis of 141 patients with stage I ovarian cancer registered in the Institute of Oncology in Gliwice from January 1985 to December 1991 was undertaken. Subsequent to the surgery 91 patients were treated by external magavoltage irradiation and 50 had no further treatment. There was no significant difference between the groups with the respect to stage and histological grade distribution. In radiotherapy group 13% developed recurrent disease comparing to 12% in control group. Adjuvant radiotherapy had no benefit in terms of relapse rate and survival. Multivariate analysis showed that dose of irradiation and the irradiated volume did not influence the prognosis.Histological grade followed by stage were the major predictors for relapse and significantly correlated with survival.