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tert-Butyl nitrite (TBN) is a nontoxic substance that has frequently been used as a source of nitrogen, oxygen, or nitric oxide (NO), but not as a carbon source in chemical transformations. Here, for the first time to the best of our knowledge, we introduced TBN as a source of carbon (tert-butyl group) for the synthesis of highly valuable N-tert-butyl amides from nitriles and water under very mild conditions. [ABSTRACT FROM AUTHOR]

We report a facile method to produce a magnetically separable graphene oxide-magnetite nanocomposite (GO-Fe3O4) and its adsorption performance in methylene blue (MB) removal from aqueous solution. The GO-Fe3O4 nanocomposite was synthesized by a solution-phase self-assembly method including the incorporation of monodisperse Fe3O4 nanoparticles (NPs) and GO in a dimethylformamide/chloroform mixture under sonication. The successfully decorating GO sheet with monodisperse Fe3O4 NPs was proved by TEM study. ICP-OES data of the GO-Fe3O4 nanocomposite show that the GO-Fe3O4 nanocomposite consists of 21 wt% Fe3O4 NPs, which is sufficient for its magnetic separation from aqueous solution. The spectroscopic studies reveal that the GO-Fe3O4 nanocomposite is a highly efficient adsorbent for MB removal from aqueous solution, providing an adsorption capacity of 172.6 mg/g, and the equilibrium for MB adsorption is attained in ~70 min. Moreover, it is a magnetically separable and reusable material for MB removal from water, preserving 87% of its initial efficiency after 5 successive runs. [ABSTRACT FROM AUTHOR]

To activate dimethyl sulfoxide (DMSO, CH3SOCH3) as a methylation agent in the C–H functionalization of (iso)quinoliniums (1), a heterogeneous photo-Fenton-like method involving the in situ generation of hydroxyl radicals by a gCN/MnO/MnO(OH) photocatalyst under visible light irradiation was realized for the first time. In the developed methodology, only a small amount of gCN/MnO/MnO(OH) photocatalysts (15 mg) was needed for the methylation of (iso)quinoliniums (1.0 mmol-scale of 1) to achieve moderate to good yields of the expected methylated-products (2) under ambient conditions. Mechanistically, hydroxyl radicals (˙OH) are produced when the gCN/MnO/MnO(OH) photocatalyst reacts with H2O and O2 under visible light illumination, and then they are added to DMSO, where they subsequently fragment into ˙CH3 radicals. The product is generated via the nucleophilic attack of the ˙CH3 radical at the most electron-deficient position of 1, followed by deprotonation reaction. The same procedure could also be used to create trideuteromethylated (iso)quinolines (3) when DMSO-d6 (CD3SOCD3) was used in place of DMSO. The presented novel strategy for DMSO or DMSO-d6 activation herein is more practical, cost-effective, and risk-free compared to the conventional Fenton reagent (H2O2 and Fe2+/Fe3+) systems available in the literature. Additionally, the gCN/MnO/MnO(OH) photocatalyst is easy to prepare, practical and economical together with being easy recoverable and reusable for several runs without considerable loss in its initial activity. [ABSTRACT FROM AUTHOR]

Black phosphorus (BP) has recently emerged as a versatile photocatalyst owing to its unique photophysical properties and tunable bandgap. Nonetheless, the rapid recombination of the photogenerated charges of pristine BP samples has significantly hindered its practical applications in photocatalysis. Herein, we report, for the first time, the effect of transition metal nanoparticles (Ni and Co) as co-catalysts on the photocatalytic activity of BP/tungsten disulfide (WS2) binary heterojunctions (BP/WS2-TM (TM: Ni, Co)) in the hydrogen evolution reaction (HER) under visible light irradiation (λ > 420 nm). Ternary heterojunctions named BP/WS2-TM (TM: Ni, Co) were synthesized via a chemical reduction method, leading to the formation of an S-scheme heterojunction, in which BP acts as a reduction catalyst and WS2 serves as an oxidation catalyst. BP/WS2-Ni and BP/WS2-Co performed substantial amounts of hydrogen generation of 9.53 mmol h−1g−1 and 12.13 mmol h−1g−1, respectively. Moreover, BP/WS2-Co exhibited about 5 and 15 times higher photocatalytic activity compared to the binary BP/WS2 heterojunctions and pristine BP, respectively. The enhanced photocatalytic activity of the heterojunction catalysts is attributed to the extended light absorption ability, enhanced charge separation, and larger active sites. This study is the first example of photocatalytic hydrogen evolution from water by using Ni- and Co-doped binary BP/WS2 heterojunctions. [ABSTRACT FROM AUTHOR]

Recently, 2D semiconductor-based heterojunctions emerge as a focal point of intensive research owing to their unique properties, including efficient charge separation and large interface areas. Herein, Ni or Co-doped black phosphorus/molybdenum disulfide (BP/MoS 2 –Y (Y: Ni, Co)) heterojunctions fabricate for photocatalytic H 2 evolution and electrochemical nitrite sensor. Compared to the BP/MoS 2 , the BP/MoS 2 –Ni and BP/MoS 2 –Co exhibit enhanced H 2 performance, as 6.4139 mmol h−1 g−1 and 7.4282 mmol h−1 g−1, respectively, in the presence of Eosin-Y (λ ≥ 420 nm). Furthermore, BP/MoS 2 –Co applies as an electrocatalyst on a GCE for the electrochemical detection of nitrite. To optimize the nitrite sensing performance of BP/MoS 2 –Co, the effect of the pH, amount of material, scan rates, and other conditions study in detail. The BP/MoS 2 –Co displays a linear response within the range of 100–2000 μM with a detection limit of 4.1 μM for DPV. This work can offer an opportunity for hydrogen systems as well as electrochemical sensor applications. • A general method is settled for fabrication of BP/MoS 2 –Y (Y: Ni, Co) heterojunctions. • BP-MoS 2 -Y heterojunctions were tested as catalysts in the photocatalytic HER. • BP-MoS 2 -Y heterojunctions were used as sensor for electrochemical nitride sensing. • A plausible mechanism was proposed for the BP-MoS 2 -Y catalyzed photocatalytic HER. [ABSTRACT FROM AUTHOR]

Summary: New photocatalysts comprising the 2D/2D heterojunction of graphitic carbon nitride (gCN) and molybdenum disulfide (MoS2) semiconductors doped with nickel (Ni) or cobalt (Co), denoted as gCN/MoS2‐M (M: Ni, Co), were fabricated for the photocatalytic hydrogen evolution reaction (HER) under visible light illumination. First, the binary gCN/MoS2 heterojunctions were fabricated by using an in‐situ solvothermal method and then they were doped with Ni or Co via a chemical reduction method. The photocatalytic HER experiments revealed that the prepared gCN/MoS2‐M (M: Ni, Co) photocatalysts showed enhanced HER activities and stabilities compared to pristine gCN and binary gCN/MoS2 heterojunctions. Total H2 productions of 5924 μmol gcat−1 and 5159 μmol gcat−1 in 8 hours were provided by using gCN/MoS2‐Ni and gCN/MoS2‐Co photocatalysts, respectively, under visible light illumination. The detailed structural characterization and examination of optical properties of gCN/MoS2‐M (M: Ni, Co) photocatalysts revealed that their enhanced photocatalytic activities were attributed to the formation of 'type‐I' 2D/2D heterojunction between gCN and MoS2 semiconductors and the creation of S‐deficient MoS2 nanostructures after Ni or Co doping, which promoted the separation of the photogenerated electron‐hole pairs, the charge mobility, and the visible light absorption. [ABSTRACT FROM AUTHOR]

The combination of inorganic (e.g., ferrite nanoparticles) and organic (e.g., conducting polymers) materials in the fabrication of heterojunctions or composites is an attractive scheme in the field of photocatalysis. We took the advantage of this phenomenon by fabricating M Ferrite (M = Co, Ni, and Zn) @polypyrrole (M Ferrite@Ppy) nanocomposites with a varying weight percentage of Ppy for the hydrogen production through photocatalytic water splitting under visible light irradiation. The structural, spectral, morphological, compositional, and optical features of the as-prepared nanocomposites were analyzed in full depth. The average crystallite sizes were estimated to be 30–40 nm from the XRD patterns which were further validated by TEM images from which a core-shell structure of the composites can be inferred. Likewise, the SEM images revealed spherical Ppy particles with a diameter in the range of 100–300 nm. From a photocatalytic viewpoint, CoFerrite@30Ppy is endowed with some peculiar characteristics including but not limited to strong light-harvesting ability (ranging between 300 and 650 nm), narrow optical band gap (as low as 1.6 eV), and higher photoluminescence (PL) lifetime (6.41 ns) which justify why it stands out among all composites in terms of photocatalysis. Under 8 h illumination of simulated visible light and using triethanolamine (TEOA) as a hole scavenger and Eosin-Y (EY) as a dye sensitizer, the photocatalytic hydrogen evolution (HER) amount for CoFerrite@30Ppy was found to be 10.44 mmol g−1, far greater than any other composite catalysts in this study. From the PL spectra, it can be pointed out that sensitization of CoFerrite with 30 wt % Ppy conduces to simultaneous deceleration of the electron-hole recombination process and acceleration of the transference of excitons within the system. [Display omitted] • A heterojunction was formed by introducing various weight % of polypyrrole (Ppy) to metal ferrites. • The photocatalytic examinations unraveled that CoFerrite with 30 wt % Ppy holds the best performance. • The best photocatalytic activity was ascribed to ideal band gap formation, longer PL lifetime, and less charge recombination. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three new hydrazone-linked two-dimensional porphyrinic COFs were constructed. • The generation of 1O 2 and O 2 •− species is selectively controlled by the COF structure. • Copper porphyrin-based COF shows the best activity in 1O 2 -involved oxidation. • COF-incorporated cobalt porphyrin exhibited the highest activity in O 2 •−-mediated oxidation. • The 1O 2 and O 2 •− generation is correlated to band structure and O 2 adsorption ability of the COFs. Regulating the generation of reactive oxygen species (ROS) impacts the selectivity and activity of photocatalytic oxidation, but the frequently concurrent formation of different types of ROS makes this process rather challenging. This study demonstrates the regulated production of two important ROS, 1O 2 and O 2 •−, using a covalent-organic framework (COF) array with three members, which are made up of metalloporphyrin cores with embedded center metal ions from d-block transition metals sequentially arranged in the periodic table. Due to the evolution of the electronic structures in this COF array, the production of 1O 2 and O 2 •− is controlled, which successively leads to distinct performance in photocatalytic aerobic oxidations. The electronic property study and density-functional theory (DFT) calculations revealed that the distinct excitonic behavior of three COFs in regulated 1O 2 and O 2 •− generation is rooted in their different band energy levels and O 2 adsorption ability. Our work presents an effective approach to the controlled production of ROS for improved photocatalytic performance. [ABSTRACT FROM AUTHOR]

Nanoparticles (NPs) have become popular photothermal therapy (PTT) photosensitizers because they can be targeted to cancer tissues and deliver a chemotherapeutic medication. Pulsed laser ablation in liquid media (PLAL) can produce stable colloidal NPs without any stabilizing agents. The stability, size distribution, and morphology of the produced colloids are influenced by the nature of NPs, laser parameters such as laser power, laser frequency repetition, ablation rate, and the specific ionic effects from the solvent. In this work, HfNbTaTiZr refractory high entropy alloy (RHEA) NPs were prepared by PLAL method in different solvents, including distilled water, ethanol, and n-hexane. The experiments were performed by irradiating a HfNbTaTiZr target with a femtosecond laser outputting 120-fs pulse at varying levels of ablation fluence (0.1, 0.16, 0.23 mJ/cm2). The elemental and structural characteristics of the prepared HfNbTaTiZr NPs were elucidated by using several advanced analytical techniques. The XRD pattern of NPs revealed that the liquid medium significantly affects the type of crystallized phases and the surface composition. The surface composition was studied by XPS, indicating that the fabricated NPs were oxidized. SEM and TEM analysis have evidenced the generation of NPs with an average diameter of less than 50 nm. The results revealed that the higher ablation fluence resulted in the formation of NPs with a larger average diameter. The highest intrinsic photothermal conversion efficiency and 12 °C time-dependent solvent heating produced in ethanol at 640 nm irradiation after 20 min were demonstrated. [Display omitted] • HfNbTaTiZr RHEA NPs prepared by Puls laser ablation in different media and ablation fluence. • The surface chemical composition of NPs after Puls laser ablation is related with ablation media. • By decreasing the ablation power, size and particle size distribution of produced NPs get smaller and narrower. • 12 °C temperature increment of NPs produced in Ethanol irradiated by 640 nm laser after 20 min was measured. [ABSTRACT FROM AUTHOR]

Recently, layered two-dimensional (2D) semiconductor materials composed of group 15 elements (pnictogens) are demonstrated as efficient photocatalysts in various applications. However, only little attention is given to the investigation of their catalytic properties, and even there is no example of the photocatalytic application of bismuthene so far. Here we report for the first time on the use of 2D bismuthene as a photocatalyst in a liquid-phase organic transformation. 2D bismuthene is proven to be an efficient photocatalyst that can be operated under various reaction conditions including indoor light illumination, darkness, outdoors and low temperature for the photoredox C–H arylation of (hetero)arenes with high product yields. The presented bismuthene catalyzed photoredox C–H arylation protocol works efficiently on a broad substrate scope of (hetero)arenes with aryl diazonium salts bearing electron-withdrawing and electron-donating groups. Moreover, a density functional theory (DFT) study reveals mechanistic details that lie behind the catalytic activity of bismuthene. [Display omitted] • Emerging of 2D bismuthene as a visible-light/NIR active heterogeneous photocatalyst. • Photoredox C-H arylation of (hetero)arenes under ambient conditions. • A photocatalyst for C-H functionalization operable in various reaction conditions. • Broad mechanistic studies on the bismuthene catalyzed photoredox C–H arylation. [ABSTRACT FROM AUTHOR]

[Display omitted] • For the first time, we report a general fabrication strategy for mpg-CN/BP-Au nanocomposites. • For the first time, the detailed electrochemical optical properties are examined. • mpg-CN/BP-Au are used as catalysts for the photocatalytic HER and electrochemical sensor. • This cheap, efficient and stable catalyst can play a role for energy conversion and sensor. We report herein the fabrication of a novel ternary nanocomposite of mesoporous graphitic carbon nitride/black phosphorus-gold nanoparticles (mpg-CN/BP-Au) and its catalytic performance in the photocatalytic hydrogen evolution reaction (HER) and electrochemical detection of paracetamol. The photocatalytic hydrogen production rate of mpg-CN/BP-Au nanocomposite (1024 µmol g−1 for 8 h) is compared with mpg-CN, mpg-CN/BP and mpg-CN/Au in the presence of triethanolamine (TEOA) as a hole scavenger under the visible light. In addition to the photocatalytic HER application, as-prepared mpg-CN/BP-Au nanocomposite was deposited on modified glassy carbon electrode (mpg-CN/BP-Au/GCE) and for the first time tested for the detection of paracetamol (PA). Under the optimum conditions, linear range of paracetamol detection was found to be in the range of 0.3–120 µM with a detection limit of 0.0425 µM. mpg-CN/BP-Au/GCE provided higher electrocatalytic activity than pristine mpg-CN and all other tested binary nanocomposites. The enhanced photo- and electrochemical activity of mpg-CN/BP-Au/GCE are attributed to formation of heterojunction between BP and mpg-CN materials. Additionally, Au nanoparticles increase the rate of adsorption of mpg-CN/BP due to the excellent electrical properties and spillover effect. We believe that the presented design and catalysis of the ternary nanocomposite will pave a way in many photo- and electrochemical applications. [ABSTRACT FROM AUTHOR]