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The direct conversion of naturally abundant carbonyl compounds provides a powerful platform for the efficient synthesis of valuable chemicals. In particular, the conversion of ketones to alkenes is a commonly encountered chemical transformation, often achieved via the multistep Shapiro reaction with tosylhydrazone and over stoichiometric organolithium or Grignard reagent. Herein, we report an earth abundant nickel-catalyzed alkenylation of naturally abundant methylene ketones to afford a wide range of alkene derivatives, mediated by hydrazine. The protocol features a broad substrate scope (including alkyl ketones, aryl ketones, and aldehydes), good functional group compatibility, mild reaction conditions, water tolerance, and only environmentally friendly N

A simple strategy to achieve remarkable activity of photoelectrochemical (PEC) water oxidation is both a critical requirement prior to accelerating the deployment of hydrogen and an important pursuit for renewable solar energy utilization. Despite various ways to improve the PEC performance, laborious fabrication and a statically driven process for water oxidation are still the most challenging tasks. We, herein, demonstrated an extremely simple but extraordinary effective strategy to boost PEC water splitting in a three-dimensional (3D) network structure (Ni foam, i.e., NF)-supported ZnO nanowire (NW)/CdS nanoparticle (NP) (NF/ZnO/CdS) photoelectrode. On the one hand, the establishment and optimization of a heteroband junction between ZnO NWs and CdS NPs substantially reduce the solar energy loss and increase the photocarrier utilization rate at the interface of two phases. On the other hand, the solution flow rotation in the unique macroporous 3D network structure gives rise to obvious piezoelectric (PE) polarization of ZnO located on the skeleton of Ni foam, which can dynamically enforce directional charge transfer. This real-time self-built PE polarization, assisted by the heteroband junction, enables the NF/ZnO/CdS photoanode system to obtain an improved photocurrent density by 12.2-fold compared with pure ZnO (at 1.23 V vs RHE). This work sheds light on an ingenious design strategy for fabricating photoelectrodes that combines a simplified structure and an effectively enhanced water oxidation performance.

An efficient oxygen reduction reaction (ORR) can be achieved by accelerating the movement of electrons, ions, reactants, and products. Here, we prepared core–shell nanohybrids with Fe0.8Zn0.2 nanop...

Recently, all-inorganic cesium lead halide perovskite CsPbX3 (X = Cl, Br, and I) colloidal nanoparticles (NPs) have attracted tremendous attention owing to their potential applications in light-emi...

Identifying effective means to improve the charge separation performance assisted by adequate surface reaction represents a significant challenge for developing a highly efficient TiO2 photoanode. Here we report a structural synergistic strategy between a close contact heterojunction and a surface oxygen vacancy to significantly boost the charge separation efficiency and charge injection efficiency of TiO2 nanowires (NWs) in PEC water splitting. To accomplish this task, a TiO2/SrTiO3 (TiO2/STO) heterojunction was first constructed by in situ conversion, resulting in close contact between interface, promoting separation of the photoinduced charge carriers, which increased charge separation efficiency by 107% compared to TiO2. After the amorphous layer was established on the surface of the SrTiO3 coating, the resulting TiO2/SrTiO3/r-SrTiO3 (TiO2/STO/r-STO) improved the light absorption property of the photoelectrodes and boosted the ability to adsorb the reactant hydroxide ions, resulting in charge injection efficiency improvement by 67.3% compared with pure TiO2. This complementary modification for enhancing charge separation and boosting the surface reaction demonstrates a significant capacity to improve the photoelectrochemical (PEC) performance of one photoanode, which could be instructive for other fields including photocatalysis and PEC carbon dioxide reduction.

The conversion of renewable resources and inexpensive inorganic chemicals directly into higher value-added organic chemicals is becoming more and more important for our society’s future sustainable development. Lignin, being the second most abundant organic carbon renewable resource on Earth, has been treated as waste in the pulp and paper industry. The 4-O-5 linkage diaryl ether bond is the strongest among the three types of ether linkages in lignins. Selective cleavage of this linkage can potentially generate smaller processable bio-based aromatic polymeric materials and compounds. Furthermore, there has been a long synthetic interest in coupling reactions with aryl ethers via C(Ar)–O bond cleavage, for example, for polyphenylene oxide (PPO) waste recycling. On the other hand, ammonia is a very inexpensive industrial inorganic chemical. Herein, we report a direct conversion of diaryl ethers and ammonia into aniline derivatives and arenes, providing a model for selective lignin 4-O-5 linkage modification...

Becasue of the existence of interface Schottky barriers and depolarization electric field, ferroelectric films sandwiched between top and bottom electrodes are strongly expected to be used as a new kind of solar cells. However, the photocurrent with a typical order of μA/cm2 is too low to be practical. Here we demonstrate that the insertion of an n-type cuprous oxide (Cu2O) layer between the Pb(Zr,Ti)O3 (PZT) film and the cathode Pt contact in a ITO/PZT/Pt cell leads to the short-circuit photocurrent increasing 120-fold to 4.80 mA/cm2 and power conversion efficiency increasing of 72-fold to 0.57% under AM1.5G (100 mW/cm2) illumination. Ultraviolet photoemission spectroscopy and dark J–V characteristic show an ohmic contact on Pt/Cu2O, an n+–n heterojunction on Cu2O/PZT and a Schottky barrier on PZT/ITO, which provide a favorable energy level alignment for efficient electron-extraction on the cathode. Our work opens up a promising new method that has the potential for fulfilling cost-effective ferroelectri...

Phase equilibrium data for the system K2Cr2O7 + CrO3 + H2O at (25 and 90) degrees C were determined by an isothermal method. The corresponding phase diagrams were plotted, and the crystallization areas were analyzed and discussed. The results show that CrO3, K2Cr2O7, K2Cr3O10, and K2Cr4O13 are present as solid phases in the system. Results from the study can be used as a basis for the separation of K2Cr2O7 and CrO3 in the cleaner production of chromium trioxide by an electrosynthesis process.