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Great interest has been attracted to enhancing the photoelectrochemical performances of BiVO4. However, there have rarely been reported about addressing their PEC stability. Herein, it is proposed that Fe ions doping could enhance the stability and PEC performances of BiVO4, which may because it could improve the crystalline structure and eliminates the crystal defects of BiVO4. Moreover, it is found that metal-organic framework can play a co-catalyst role during the PEC experiments. We designed and fabricated nanoporous Fe-doped BiVO4 modified with MIL-53(Fe), which exhibits much higher PEC performance and stability than pristine BiVO4 and Fe-doped BiVO4. It is believed that MIL-53(Fe) can capture the photogenerated holes and thus facilitates the charge separation efficiency.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Abstract: Great efforts have been paid to improve the photoelectrochemical performances of FeVO4 semiconductors. However, there have rarely been reported about the modifying of FeVO4 with metal-free co-catalyst for enhanced photoelectrochemical activities. Herein, we demonstrate a facile and effective immersion method for coupling ultrathin g-C3N4 nanosheets with nanoporous FeVO4 photoelectrodes. The FeVO4/g-C3N4 heterostructures demonstrate more than twice higher photocurrent density than pure nanoporous FeVO4 photoelectrodes, which should be attributed to the metal-free co-catalyst of ultrathin g-C3N4. It is believed that the ultrathin g-C3N4 nanosheets can effectively trap the photo excited holes and facilitates the charge separation efficiency and thus significantly improve the photoelectrochemical performances of FeVO4.Graphical Abstract: [ABSTRACT FROM AUTHOR]

In this study, transparent p-type CuCrxOy semiconductor thin films were fabricated using spin coating and integrated as channel layers in thin-film transistors (TFTs). The structural, morphological components, and optical properties of CuCrxOy thin films, together with device performance, were systematically investigated. The phase conversion from a mixture of CuCr2O4 and CuO to pure CuCrO2 was achieved when the annealing temperature (Ta) was higher than 700 °C. The electrical performance of the CuCrxOy TFTs on SiO2 dielectric is improved with increasing Ta from 500 °C to 800 °C. The optimized CuCrO2 TFT exhibits an on/off current ratio of ∼105 and a hole mobility of 0.59 cm2 V−1 s−1, which is much better than those previous works on solution-processed binary CuxO TFTs. To our best knowledge, this work demonstrates the ternary p-type CuCrO2 TFTs fabricated via a low-cost solution process for the first time, which represents an important advancement towards the development of all-oxide, low-cost p–n junctions and CMOS logic circuits. [ABSTRACT FROM AUTHOR]

Although there are a few research studies on solution-processed p-channel oxide thin-film transistors (TFTs), the strict fabrication conditions and the poor electrical properties have limited their applications in low-power complementary metal oxide semiconductor (CMOS) electronics. Here, the application of the polyol reduction method for processing p-type CuxO and NiOx channel layers and their implementation in TFT devices are reported. The optimized CuxO and NiOx TFTs were achieved at low annealing temperatures (∼300 °C) and exhibited decent electrical properties. Encouraged by the inspiring results obtained on SiO2/Si substrates, the TFT performance was further optimized by device engineering, employing high-k AlOx as the gate dielectric. The fully solution-processed NiOx/AlOx TFT could be operated at a low voltage of 3.5 V and exhibits a high hole mobility of around 25 cm2 V−1 s−1. Our work demonstrates the ability to grow high-quality p-type oxide films and devices via the polyol reduction method over large area substrates while at the same time it provides guidelines for further p-type oxide material and device improvements. [ABSTRACT FROM AUTHOR]

Photosynthetic CO fixation is the ultimate source of organic carbon on earth and thus is essential for crop production and carbon sequestration. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the first step of photosynthetic CO fixation. However, the extreme low carboxylation efficiency of Rubisco makes it the most attractive target for improving photosynthetic efficiency. Extensive studies have focused on re-engineering a more efficient enzyme, but the effort has been impeded by the limited understanding of its structure-function relationships and the lack of an efficient selection system towards its activity. To address the unsuccessful molecular engineering of Rubisco, we developed an Escherichia coli-based activity-directed selection system which links the growth of host cell solely to the Rubisco activity therein. A Synechococcus sp. PCC7002 Rubisco mutant with E49V and D82G substitutions in the small subunit was selected from a total of 15,000 mutants by one round of evolution. This mutant showed an 85% increase in specific carboxylation activity and a 45% improvement in catalytic efficiency towards CO. The small-subunit E49V mutation was speculated to influence holoenzyme catalysis through interaction with the large-subunit Q225. This interaction is conserved among various Rubisco from higher plants and Chlamydomonas reinhardtii. Knowledge of these might provide clues for engineering Rubisco from higher plants, with the potential of increasing the crop yield. [ABSTRACT FROM AUTHOR]

Large-conductance voltage- and Ca2+-gated K+ channels are negative-feedback regulators of excitability in many cell types. They are complexes of a subunits and of one of four types of modulatory β subunits. These have intracellular N- and C-terminal tails and two transmembrane (TM) helices, TM1 and TM2, connected by an ~100-residue extracellular loop. Based on endogenous disulfide formation between engineered cysteines (Cys), we found that in β2 and β3, as in β1 and β4, TM1 is closest to αSl and αS2 and TM2 is closest to αSO. Mouse β3 (mβ3) has seven Cys in its loop, one of which is free, and this Cys readily forms disulfides with Cys substituted in the extracellular flanks of each of αS0-αS6. We identified by elimination mβ3-loop Cysl52 as the only free Cys. We inferred the disulfide-bonding pattern of die other six Cys. Using directed proteolysis and fragment sizing, we determined this pattern first among the four loop Cys in β1. These are conserved in β2-β4, which have four additional Cys (eight in total), except that mβ3 has one fewer. In βi, disulfides form between Cys at aligned positions 1 and 8 and between Cys at aligned positions 5 and 6. In mβ3, the free Cys is at position 7; position 2 lacks a Cys present in all other β2-β4; and die disulfide pattern is 1-8, 3-4, and 5-6. Presumably, Cys 2 cross-links to Cys 7 in all other β2-β4. Cross-linking of mβ3 Cysl52 to Cys substituted in die flanks of αS0-S5 attenuated the protection against iberio-toxin (IbTX); cross-linking of Cysl52 to K296C in the βS6 flank and close to the pore enhanced protection against IbTX. In no case was N-type inactivation by the N-terminal tail of mβ3 perturbed. Although the mβ3 loop can move, its position with Cysl52 near αK296, in which it blocks IbTX binding, is likely favored. [ABSTRACT FROM AUTHOR]

Piezocatalysis has been regarded as a great potential tool in water pollution treatment. In this report, eco-friendly piezoelectric 0.93(Bi 1/2 Na 1/2)TiO 3 -0.07BaTiO 3 (BNBT) nanofibers were prepared by electrospinning and calcined at various temperatures. The piezocatalytic activities of the BNBT nanofibers were examined by the degradation of various dyes. It is indicated that the BNBT nanofibers calcined at 650 °C exhibit the optimum piezocatalytic performance and a degradation rate of 0.0518 min−1 is achieved for Acid Orange 7. The kinetic investigations reveal that the sorption of the dye molecules on the surfaces of the nanofibers can be suppressed by increasing the initial concentration or ionic strength of the dye solution, thus the piezocatalytic degradation efficiency is deteriorated. While the pH value of the reaction system plays an insignificant role in the piezocatalytic degradation process. Moreover, the electrospun BNBT nanofibers exhibit a good reusability and wide universality for the piezocatalytic degradation, which is important for the practical applications. This work provides an in-depth understanding of the piezocatalytic mechanisms in the degradation of the organic dyes and opens a new route for the development of high-performance and eco-friendly piezocatalysts. Image 1 • Electrospun BNBT nanofiber calcined at 650 °C exhibited the optimum piezocatalytic performance. • Kinetic influences on piezocatalytic performance were established for BNBT nanofibers. • BNBT nanofibers exhibited a good piezocatalytic reusability, and were available for relatively weak actions. [ABSTRACT FROM AUTHOR]