A multi-functional layered double hydroxide (LDH)-modified BiVO4 photoanode exhibits a tremendous cathodic shift of the onset potential and more than 2-fold enhancement in the oxidation efficiency and IPCE value.

The development of earth-abundant semiconductor photoelectrodes is of great importance to high-efficiency and sustainable photoelectrochemical water splitting. Herein, a one-dimensional TiO2 array photoanode was sheathed with an ultrathin overlayer of phosphated nickel-chromium double-metal hydroxide by a photoassisted modification and deposition strategy. The core/shell array photoanode resulted in a large cathodic shift of photocurrent onset potential (≈200 mV). Nearly 100 % oxidative efficiency for PEC water oxidation was achieved over a wide range of potential. Mechanism studies show that the modification of phosphate leads to significantly improved charge separation. The amorphous hydroxide sheath could efficiently inhibit oxygen reduction reactions. Therefore, this strategy enables the simultaneous suppression of surface carrier recombination and back reactions, which is promising to improve the water oxidation efficiency of currently prevailing photoanodes.

Hydrotalcite-supported platinum nanocrystals (Pt NCs) were synthesized by a facile solution chemistry method, and then applied as an efficient catalyst for the selective hydrogenation of cinnamaldehyde (CMA) in neat water. The reduction of metal precursor ions was achieved in an aqueous solution at a low temperature (323 K), simultaneously accompanied by the crystallization of the hydrotalcite support. The size of the Pt NCs can be delicately tuned by the relative ratio of surfactant to metal precursor ions, and characterized by HRTEM and CO-adsorption infrared spectroscopy. The Pt particle sizes are closely associated with the hydrogenation selectivity toward cinnamyl alcohol (CMO), with a higher selectivity up to 85% over the larger-sized Pt in an aqueous medium. The effects of alkali (NaOH) on the catalytic performance were explored. The findings indicated that the addition of alkali enhances the selectivity toward CMO (to 90%). The catalysts showed high stability with a marginal decrease in activity and selectivity after repeated use. The hydrogenation products could be easily separated from the solvent by simple extraction, which is a greener and more convenient process than those using organic solvents.

At the late 1940s, 17β-HSD1 was discovered as the first member of the 17β-HSD family with its gene cloned. The three-dimensional structure of human 17β-HSD1 is the first example of any human steroid converting enzyme. The human enzyme's structure and biological function have thus been studied extensively in the last two decades. In humans, the enzyme is expressed in placenta, ovary, endometrium and breast. The high activity of estrogen activation provides the basis of 17β-HSD1's implication in estrogen-dependent diseases, such as breast cancer, endometriosis and non-small cell lung carcinomas. Its dual function in estrogen activation and androgen inactivation has been revealed in molecular and breast cancer cell levels, significantly stimulating the proliferation of such cells. The enzyme's overexpression in breast cancer was demonstrated by clinical samples. Inhibition of human 17β-HSD1 led to xenograft tumor shrinkage. Unfortunately, through decades of studies, there is still no drug using the enzyme's inhibitors available. This is due to the difficulty to get rid of the estrogenic activity of its inhibitors, which are mostly estrogen analogues. New non-steroid inhibitors for the enzyme provide new hope for non-estrogenic inhibitors of the enzyme.

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The hydrogenation of α,β-unsaturated aldehydes to allylic alcohols or saturated aldehydes provides a typical example to study the catalytic effect on structure-sensitive reactions. In this work, supported platinum nanocatalysts over hydrotalcite were synthesized by an alcohol reduction method. The Pt catalyst prepared by the reduction with a polyol (ethylene glycol) outperforms those prepared with ethanol and methanol in the hydrogenation of cinnamaldehyde. The selectivity towards the C=O bond is the highest over the former, although its mean size of Pt particles is the smallest. The hydroxyl groups on hydrotalcite could act as an internally accessible promoter to enhance the selectivity towards the C=O bond. The optimal Pt catalyst showed a high activity with an initial turnover frequency (TOF) of 2.314 s(-1). This work unveils the synergic effect of metal valence and in situ promoter on the chemoselective hydrogenation, which could open up a new direction in designing hydrogenation catalysts.

Host–guest photofunctional materials have received much attention recently due to their potential applications in light emitting diodes, polarized emission, and other optoelectronic fields. In this work, we report the encapsulation of a photoactive ruthenium-based complex (4,4′-diphosphonate-2,2′-bipyridine) into the biphenyl-based metal–organic framework (MOF) as a host–guest material toward potential photofunctional applications. The resulting material (denoted as Ru@MOF) presents different two-color blue/red luminescences at the crystal interior and exterior as detected by three-dimensional confocal fluorescence microscopy. Additionally, up-conversion emission and an enhanced photoluminescence lifetime relative to the pristine Ru-based complex can also be observed in this Ru@MOF system. Upon attaching on the rutile TiO2 nanoarray, the Ru@MOF also exhibits alternated photoelectrochemical properties relative to the pristine complex. Moreover, a density functional theoretical calculation was performed on the Ru@MOF structure to provide understanding of the host–guest interactions. Based on the combination of experimental and theoretical studies on the Ru@MOF system, the aim of this work is to deeply investigate how the host–guest materials can present different photofunctionalities and optoelectronic properties compared with those of the individual components, and to give detailed information on the potential host–guest energy/electronic transfer between the MOF and the complex.

Two native epoxide hydrolases (EHs) were previously discovered from mung bean powder (Vigna radiata), both of which can catalyze the enantioconvergent hydrolysis of p-nitrostyrene oxide (pNSO). In this study, the encoding gene of VrEH1 was successfully cloned from the cDNA of V. radiata by RT-PCR and rapid amplification of cDNA ends (RACE) technologies. High homologies were found to two putative EHs originated from Glycine max (80%) and Medicago truncatula (79%). The vreh1 gene constructed in pET28a(+) vector was then heterologously overexpressed in Escherichia coli BL21(DE3), and the encoded protein was purified to homogeneity by nickel affinity chromatography. It was shown that VrEH1 has an optimum activity at 45 °C and is very thermostable with an inactivation energy of 468 kJ mol(-1). The enzyme has no apparent requirement of metal ions for activity, and its activity was strongly inhibited by 1 mM of Ni(2+), Cu(2+), Fe(2+), or Co(2+). By adding 0.1% Triton X-100, the enzyme activity could be significantly increased up to 340%. VrEH1 shows an unusual ability of enantioconvergent catalysis for the hydrolysis of racemic pNSO, affording (R)-p-nitrophenyl glycol (pNPG). It displays opposite regioselectivity toward (S)-pNSO (83% to Cα) in contrast to (R)-pNSO (87% to Cβ). The K M and k cat of VrEH1 were determined to be 1.4 mM and 0.42 s(-1) for (R)-pNSO and 5.5 mM and 6.2 s(-1) for (S)-pNSO. This thermostable recombinant VrEH1 with enantioconvergency is considered to be a promising biocatalyst for the highly productive preparation of enantiopure vicinal diols and also a good model for understanding the mechanism of EH stereoselectivity.