Rutile TiO2 is a promising photocatalyst due to its narrower band gap, higher thermodynamic stability and fewer intragrain defects. However, it has not yet to achieve comparable photocatalytic activity to anatase TiO2 owing to its higher recombination rate of electron-hole pairs. In order to effectively separate the electron-hole pairs in rutile TiO2, we propose a facet heterojunction (FH) structure to prolong the lifetime of photogenerated electrons. Ultrathin TiO2 nanosheets with different facets were in-situ coated on TiO2 nanorod substrates, where facet heterojunctions are built among nanosheets as well as between nanosheets and nanorod substrates. The as-prepared rutile TiO2 with FH mechanism (FH-TiO2) served as an effective photocatalyst for water splitting. More than 45 and 18 times higher of photogenerated current density and H2 production rate were obtained respectively, compared to pure rutile TiO2 nanorod. Moreover, FH-TiO2 delivered 0.566 mmol g -1 h -1 H2

The coexistence of ferroelectricity and magnetism in VOCl2 monolayer which is mechanically strippable from the bulk material offers a tantalizing potential for high-density multistate data storage.

The high energy density, low cost, and environmental friendliness of lithium–sulfur (Li–S) batteries enable them to be promising next-generation energy storage systems. However, the commercialization of Li–S batteries is presently hindered by the bottlenecks, such as the low conductivity of sulfur species, shuttle effect of polysulfides, and poor conversion efficiency in discharging/charging processes. Here, on the basis of first-principles calculations, we predicted that the two-dimensional magnetic Fe3GeX2 (X = S, Se, and Te) monolayers are quite promising to overcome the aforesaid problems. The Fe3GeX2 monolayer has metallic electronic structures and moderate binding strength to the soluble lithium polysulfides, which are expected to improve the overall electric conductivity of sulfur species and anchor the soluble lithium polysulfides to suppress the shuttle effect. Remarkably, Fe3GeX2 monolayers show bifunctional electrocatalytic activity to the S reduction reaction and the Li2S decomposition reaction, which improves the conversion efficiency in discharging and charging processes. This finding may open up an avenue for the development of high-performance Li–S batteries.

We demonstrated from first-principles the C3N5 multilayers as high-efficient photocatalysts for overall water splitting. The redox ability of the photogenerated carriers is high enough to drive HER and OER without using sacrificial reagents.

This review article critically discusses examples of asymmetric synthesis of tailor-made α-amino acids via homologation of Ni(II) complexes of glycine and alanine Schiff bases, reported in the literature from 2013 through the end of 2016. Where it is possible, reaction mechanism and origin of the stereochemical outcome is discussed in detail. Special attention is given to various aspects of practicality and scalability of the reported methods. Among the most noticeable developments in this area are novel designs of axially chiral ligands, application of electro- and mechano-chemical (ball-milling) conditions, and development of dynamic kinetic resolution procedures.

Photocatalytic CO2 conversion into reproducible chemical fuels (e.g., CO, CH3OH, or CH4) provides a promising scheme to solve the increasing environmental problems and energy demands simultaneously. However, the efficiency is severely restricted by the high overpotential of the CO2 reduction reaction (CO2RR) and rapid recombination of photoexcited carriers. Here, we propose that a novel type-II photocatalytic mechanism based on two-dimensional (2D) ferroelectric multilayers would be ideal for addressing these issues. Using density-functional theory and nonadiabatic molecular dynamics calculations, we find that the ferroelectric CuInP2S6 bilayers exhibit a staggered band structure induced by the vertical intrinsic electric fields. Different from the traditional type-II band alignment, the unique structure of the CuInP2S6 bilayer not only effectively suppresses the recombination of photogenerated electron–hole (e–h) pairs but also produces a sufficient photovoltage to drive the CO2RR. The predicted recombination time of photogenerated e–h pairs, 1.03 ns, is much longer than the transferring times of photoinduced electrons and holes, 5.45 and 0.27 ps, respectively. Moreover, the overpotential of the CO2RR will decrease by substituting an S atom with a Cu atom, making the redox reaction proceed spontaneously under solar radiation. The solar-to-fuel efficiency with an upper limit of 8.40% is achieved in the CuInP2S6 bilayer and can be further improved to 32.57% for the CuInP2S6 five-layer. Our results indicate that this novel type-II photocatalytic mechanism would be a promising way to achieve highly efficient photocatalytic CO2 conversion based on the 2D ferroelectric multilayers.

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Intrinsic polarized Li-III-VI bilayers as highly efficient photocatalysts for overall water splitting.