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The first ring-opening addition of a benzylic C(sp3)–H bond to azabenzonorbornadienes is demonstrated. The reaction proceeded under the catalytic system of [Cp*CoI2(CO)], AgSbF6 and Fe(OAc)2 in PhOMe. The methodology showed a good substrate scope with up to 96% yield. The relative configuration of the product was determined as cis-configuration by X-ray crystallography. [ABSTRACT FROM AUTHOR]

An Ni–Zn battery is a distinguished member in the family of closed Zn-based batteries due to its ideal power density and voltage. However, when it is employed as a power supply for electric vehicles, its defects in terms of specific capacitance and energy density become obvious. Herein, to resolve this problem, a hybrid battery system was created through a combination of Ni–Zn and Zn–air batteries at the cell level. In a hybrid battery system, oxygen vacancy rich NiO with S,N co-modified mesoporous carbon as a matrix was used as the cathode material. This cathode material showed a high specific capacitance of 202.1 mA h g−1 at 1.0 A g−1. When the current density reduces to 20 A g−1, this value decreases to 130.2 mA h g−1, which implies that 64.4% of specific capacitance was retained. It also exhibits excellent OER and ORR activities. For the hybrid battery system, when the discharge process was carried out at 1 mA cm−2, there were two voltage plateaus at 1.72 and 1.12 V, which originated from Ni–Zn and Zn–air, respectively. In this case, its specific capacitance and energy density reaches 800.3 mA h g−1 and 961 W h kg−1, respectively. The hybrid battery also possesses perfect stability during multi-cycle charge–discharge tests. The construction of this hybrid battery system develops a new road to prepare a power supply device with high performance. [ABSTRACT FROM AUTHOR]

1,3-Pentadiene (piperylene) is an important monomer in the manufacturing of adhesives, plastics, and resins. It can be derived from biomass by the tandem ring-opening and dehydration (dehydra-decyclization) of 2-methyltetrahydrofuran (2-MTHF), but competing reaction pathways and the formation of another isomer (1,4-pentadiene) have limited piperylene yields to <60%. In this report, using detailed kinetic measurements of 2-MTHF dehydra-decyclization on zeolites with disparate acidities (boro-, and alumino-silicates) and micropore environments (MFI, MWW, and BEA), weakly acidic borosilicates were shown to exhibit ca. 10–30% higher selectivity to dienes at about five-to-sixty times lower proton-normalized rates than aluminosilicates (453–573 K). Dehydra-decyclization site time yields (STYs) were invariant for aluminosilicates within the investigated frameworks, indicating the absence of pore-confinement influence. However, individual site-normalized reaction rates varied by almost an order of magnitude on borosilicates in the order MWW > MFI > BEA at a given temperature (523 K), indicating the non-identical nature of active sites in these weak solid acids. The diene distribution remained far from equilibrium and was tuned towards the desirable conjugated diene (1,3-pentadiene) by facile isomerization of 1,4-pentadiene. This tuning capability was facilitated by high bed residence times, as well as the smaller micropore sizes among the zeolite frameworks considered. The suppression of competing pathways, and promotion of 1,4-pentadiene isomerization events lead to a hitherto unreported ∼86% 1,3-pentadiene yield and an overall ∼89% combined linear C5 dienes' yield at near quantitative (∼98%) 2-MTHF conversion on the borosilicate B-MWW, without a significant reduction in diene selectivities for at least 80 hours time-on-stream under low space velocity (0.85 g reactant per g cat. per h) and high temperature (658 K) conditions. Finally, starting with iso-conversion levels (ca. 21–26%) and using total turnover numbers (TONs) accrued over the entire catalyst lifetime as the stability criterion, borosilicates were demonstrated to be significantly more stable than aluminosilicates under reaction conditions (∼3–6× higher TONs). [ABSTRACT FROM AUTHOR]

Visible light mediated oxidative dehydrogenation of hydrazobenzenes under an ambient atmosphere using an organic dye as a photocatalyst was reported for the first time. The reaction provides an environmentally benign method for the preparation of azobenzenes in excellent yields with good functional group tolerance. [ABSTRACT FROM AUTHOR]

The traditional analytical biosensor instruments are relatively bulky, expensive, and not easy to handle, thus their applications are largely limited in resource-limited settings. The recent development of microfluidic lab-on-a-chip (LOC) technology has provided a possible solution to miniaturize the conventional biosensing system, yet other accessory devices to detect, readout, analyze, transfer, and display results are still required. With the rapid development, mass production, and pervasive distribution of smartphones in recent years, they have provided people with portable, cost-effective, and easy-to-operate platforms to build analytical biosensors for point-of-care (POC) applications and mobile health. Based on the common analytical methods, this paper reviews the recent development of four types of smartphone based analytical biosensory systems at the POC, i.e., smartphone-based microscopic imaging, colorimetric, electrochemical, and electrochemiluminescence biosensor. The different bio-sensing strategies and analytical performance together with future perspectives are discussed. [ABSTRACT FROM AUTHOR]

Herein, Fe3O4–inositol hexaphosphate (Fe3O4–IP6) was fabricated via layer-by-layer electrostatic self-assembly following a solvothermal synthesis method and via a one-step co-precipitation method. The influence of the synthesis method on the controlled drug release and combination therapeutic behaviour of Fe3O4–IP6 was characterized. The two preparation methods resulted in differences in the compound color, particle size, magnetic properties, and drug loading capacity with an optimum initial drug concentration. The sample prepared via the one-step co-precipitation method exhibited a magnetic saturation of 39.23 emu g−1, higher drug loading efficiency for doxorubicin (DOX), and improved anticancer effects than that prepared via the alternative method. However, Fe3O4–IP6 prepared via both methods showed obvious pH sensitivity in weak acidic regions such as tumour tissue, leading to marked inhibition of the regeneration of tumour cells without adverse effects. [ABSTRACT FROM AUTHOR]

A surfactant and substrate synergetic chemical solution technique was promoted to synthesize uniformly shaped MOF nanodisks. The hexaprismatic nanodisks of {[Eu2(MFDA)2(HCOO)2(H2O)6]·H2O}n (Eu-MFDA_HND, H2MFDA = 9,9-dimethyl fluorene-2,7-dicarboxylic acid) were obtained on a supported substrate in the presence of sodium dodecyl sulfate. The surfactant and substrate worked together to produce the uniform hexaprismatic shaped products, but in contrast, mixed products of defected hexaprisms and irregular nanoparticles were obtained without the substrate. Also, the dehydrated Eu-MFDA_HND crystals showed a much higher fluorescence quenching efficiency towards 2,4-DNT as compared to their corresponding bulk crystals. This effective morphology-scissoring technique may help the shape control of other functional MOF materials and benefit their application in the fields of catalysis, sensing, optoelectronic microdevices, micromechanical devices, etc. [ABSTRACT FROM AUTHOR]

Herein, a type of π-system based fluorescent coordination polymer hollow nanospheres of terbium 1,3,5-benzenetrisbenzolate (TbBTB) was synthesized through a solvothermal process, and the nanospheres exhibited a good sensing performance for the detection of explosive aromatic nitro-compounds, as compared to aliphatic nitro-compounds as well as the small organic solvent molecules of dimethyl sulfoxide, chloroform and tetrahydrofuran. FESEM and TEM results showed that the spheres are 300–600 nanometers in diameter and they are composed of small nanoparticles of coordination polymer. The formation of the spheres is driven by the Ostwald ripening process under solvothermal conditions according to a series of corresponding control experiments. The sensing of aromatic nitro explosives may benefit from the special features of the nanospheres, which possess an intrinsic π-system of both π-conjugated ligands and intermolecular π–π stacking interactions, as well as their multiscale-porosity. This study may benefit the screening or design of fluorescent sensors for aromatic and aliphatic explosive nitro-compounds. [ABSTRACT FROM AUTHOR]

A series of Ni@g-C3N4 composites were synthesized by a simple solvent thermal method using melamine and acetylacetone nickel as precursors. The results of X-ray diffraction, transmission electron microscopy and high resolution transmission electron microscopy indicate that Ni was successfully loaded on g-C3N4. And the Ni loaded greatly enhances the photocatalytic H2 evolution activity of g-C3N4 compared to the pure g-C3N4. In order to study the role of Ni, the surface photovoltage, the surface photocurrent and photoluminescence measurements were used to investigate the photogenerated charge properties of g-C3N4. What is more, Mott–Schottky plots and work function measurements confirmed the surface band bending change of g-C3N4 contacting with Ni. Those results demonstrate that Ni coating deepens surface band bending of g-C3N4, resulting in higher separation efficiency of photogenerated charge carriers, which is contributed to the enhanced photocatalytic H2 evolution activity. [ABSTRACT FROM AUTHOR]

For semiconductor-based PEC systems, loading an appropriate cocatalyst on a semiconductor (such as a solar-active material) can significantly improve the PEC activity due to the suppression of photogenerated charge recombination. But there is little direct information about the role of a cocatalyst in the spatial separation of photogenerated charge carriers. In our work, a combination of surface photovoltage spectroscopy (SPS), transient photovoltage (TPV) technique, photoelectrochemical impedance spectroscopy (PEIS) and transient photocurrent measurements was used to study the real role of Ni(OH)2 as a cocatalyst for the enhanced PEC performance of Ni(OH)2-modified Ti-doped α-Fe2O3. It was found that Ni(OH)2 as a hole storage layer enhances the separation of photogenerated charge carriers and increases the lifetime of holes, which contributed to the enhanced photocurrent. In addition, Ni(OH)2 is a good cocatalyst for urea oxidation which suppresses the over-potential, resulting in a negative shift of the onset potential. [ABSTRACT FROM AUTHOR]

The composite Bi2O3/ZnO photocatalyst, a novel p–n type heterojunction with different molar ratios of Bi to Zn, has been fabricated using a hydrothermal method. The XRD, XPS, UV-vis DRS, SEM, HRTEM studies were used to characterize the as-obtained products. The photocatalytic activities of the p-Bi2O3/n-ZnO heterojunctions were investigated for their efficiency on the degradation of alizarin red (AR) dye under visible light irradiation (λ ＞ 420 nm), and the results showed that the composites possessed remarkable photocatalytic activities, which were conducive to their separation, recycling, and reuse. The photogenerated charge-transfer properties were tested by surface photocurrent (SPC) and surface photovoltage (SPV) experiments and results show that the interfacial electric field located between Bi2O3 and ZnO played an important role in promoting the separation of photogenerated electron and hole pairs. These results are helpful to design and construct high efficiency heterogeneous semiconductor photocatalysts. [ABSTRACT FROM AUTHOR]

Triphenylamine (TPA) dyes usually show relatively narrow spectral response range with respect to indoline and porphyrin based dyes. To optimize light-harvesting, WS62 and WS64 are molecularly engineered on the basis of D-A- Π-A model. We employ TPA in the absence or presence of long alkoxy-chain as the electron donor, benzoxadiazole as the auxiliary acceptor, a 4H-cyclopenta[2,1-b:3,4-b"]dithiophene (CPDT) unit as the Π-bridge, and cyanoacetic acid as the anchor group. The incorporated electron-withdrawing unit of benzoxadiazole enhances light harvesting by decreasing the molecular energy gap and red-shifting absorption spectra. Moreover, three D- Π-A-featured dyes (S0, S1 and S2) with different length of the Π-bridge are developed as co-sensitizers for WS62 and WS64. As demonstrated, the co-sensitization effect is critically dependent upon the Π-conjunction length in the three co-adsorbent dyes. Dye S2 containing dithiophene unit as the Π-bridge shows a promising co-sensitization result for enhancing photovoltaic efficiency. In contrast, S1 and S0 with fewer thiophene units negatively contribute to photovoltaic performances. The cocktail co-sensitization of WS62 and WS64 with S2 can compensate the peak valley of IPCE adsorbed by electrolyte near 400 nm and compact the surface of TiO2 to retard charge recombination, essentially for the optimization of photovoltaic performances. Solar cells based on the co-sensitization of WS64 and S2 show a high efficiency of 7.9% (VOC of 738 mV, JSC of 14.9 mA cm-2 and FF of 0.72), exhibiting a significant improvement by 41% compared to the WS64 alone sensitized devices under the same conditions. The charge transfer resistance (RCT) of the co-sensitized DSSCs is larger than that of DSSC comprising only WS62 or WS64 by around 10-fold, indicating that the unfavourable charge transfer from TiO2 to electrolyte is efficiently blocked by the cocktail co-sensitization of S2. These findings pave a way regarding how to choose the proper and matchable co-sensitizers for further increasing the photovoltaic performances of pure organic sensitizers. [ABSTRACT FROM AUTHOR]

The first ring-opening addition of a benzylic C(sp 3 )-H bond to azabenzonorbornadienes is demonstrated. The reaction proceeded under the catalytic system of [Cp*CoI 2 (CO)], AgSbF 6 and Fe(OAc) 2 in PhOMe. The methodology showed a good substrate scope with up to 96% yield. The relative configuration of the product was determined as cis-configuration by X-ray crystallography.

In our work, blue photoluminescent N-doped carbon dots (CDs) were developed via a green and simple hydrothermal method with citric acid and polyvinyl pyrrolidone (PVP K-30) as the carbon source and the nitrogen source, respectively. The as-prepared CDs have a high fluorescent quantum yield of 30.21% and considerable luminescence stability. The fluorescence intensity of the CDs was found to be effective quenched when adding Fe 3+ ions to the CDs solution. The quenching phenomenon can be used to detect Fe 3+ ions within a linear range of 0-300 μM with a detection limit of 45.5 nmol L -1 , which suggested its potential application in the detection of Fe 3+ ions. At the same time, we also noted the excellent self-quenching-resistant property of the as-prepared CDs in the solid state, and bright blue fluorescence was observed under UV excitation. What's more, the as-prepared CDs can also be used as fluorescent ink and were presented under UV excitation., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A series of Ni@g-C3N4 composites were synthesized by a simple solvent thermal method using melamine and acetylacetone nickel as precursors. The results of X-ray diffraction, transmission electron microscopy and high resolution transmission electron microscopy indicate that Ni was successfully loaded on g-C3N4. And the Ni loaded greatly enhances the photocatalytic H2 evolution activity of g-C3N4 compared to the pure g-C3N4. In order to study the role of Ni, the surface photovoltage, the surface photocurrent and photoluminescence measurements were used to investigate the photogenerated charge properties of g-C3N4. What is more, Mott-Schottky plots and work function measurements confirmed the surface band bending change of g-C3N4 contacting with Ni. Those results demonstrate that Ni coating deepens surface band bending of g-C3N4, resulting in higher separation efficiency of photogenerated charge carriers, which is contributed to the enhanced photocatalytic H2 evolution activity.

For semiconductor-based PEC systems, loading an appropriate cocatalyst on a semiconductor (such as a solar-active material) can significantly improve the PEC activity due to the suppression of photogenerated charge recombination. But there is little direct information about the role of a cocatalyst in the spatial separation of photogenerated charge carriers. In our work, a combination of surface photovoltage spectroscopy (SPS), transient photovoltage (TPV) technique, photoelectrochemical impedance spectroscopy (PEIS) and transient photocurrent measurements was used to study the real role of Ni(OH)2 as a cocatalyst for the enhanced PEC performance of Ni(OH)2-modified Ti-doped α-Fe2O3. It was found that Ni(OH)2 as a hole storage layer enhances the separation of photogenerated charge carriers and increases the lifetime of holes, which contributed to the enhanced photocurrent. In addition, Ni(OH)2 is a good cocatalyst for urea oxidation which suppresses the over-potential, resulting in a negative shift of the onset potential.