A Novel Approach for Achieving High‐Efficiency Photoelectrochemical Water Oxidation in InGaN Nanorods Grown on Si System: MXene Nanosheets as Multifunctional Interfacial Modifier

MXene nanosheets with attractive electrical conductivity and tunable work function have been adopted as multifunctional interfacial modifier between InGaN nanorods and Si for photoelectrochemical water oxidation for the first time. Compared to bare InGaN/Si systems, MXene interfacial layers give rise to an ultralow onset potential of 75 mV versus reversible hydrogen electrode (RHE), which is the highest ever reported for InGaN‐ or Si‐based photoanodes by interfacial modification. Furthermore, the modified photoanode exhibits a significantly enhanced photocurrent density (7.27 mA cm^?2) at 1.23 V versus RHE, which is about 10 times higher than that achieved with the InGaN/Si photoanode. The detailed mechanism demonstrates that the formed type‐II band alignment in InGaN/MXene heterojunction and an Ohmic junction at the MXene/Si interface make MXene an ideal electron‐migration channel to enhance charge separation and transfer process. This synergetic effect of MXene can significantly decrease the charge resistance at semiconductor/Si and semiconductor/electrolyte hetero‐interfaces, eventually resulting in the fast hole injection efficiency of 82% and superior stability against photocorrosion. This work not only provides valuable guidance for designing high‐efficiency photoelectrodes through the integration of multiscale and multifunctional materials, but also presents a novel strategy for achieving high‐performance artificial photosynthesis by introducing interfacial modifier.     

Lithiothermic-Synchronous Construction of Mo-Li2S-Graphene Nanocomposites for High-Energy Li2S//Si?C Battery

Reducing the activation barrier and stabilizing the sulfur species of Li₂S cathodes can ultimately enhance cell efficiency and the cycle life of S-based Li-ion batteries (LIBs). Here, a unique synchronous synthesis method is established that can simultaneously construct Li₂S encapsulated in conductive protective layers, and accordingly propose a coordination effect of catalysis and domain restriction for Li₂S cathodes. Typically, based on the lithiothermic reaction of 8Li + MoS₂ + CS₂ = 4Li₂S + Mo + C, the obtained composite features abundant Mo nanocrystals embedded in crystalline Li₂S matrices and then wrapped by few-layer graphene. Notably, all three components derived from lithiothermic reaction are linked by the chemical bonding of Mo? S and C? S, forming a compact Mo-Li₂S-graphene triple heterostructure. Systematic studies reveal an unprecedented relevancy between charge overpotential and catalytic activation of Mo-Li₂S-graphene, whereas a low activation potential of 2.43 V is achieved. Further studies disclose the relationship between cycle stability and confinement effect of core-shell structure, whereas the improved confinement efficiency for polysulfides enables an excellent cycle life for the Li-S battery. Moreover, the Mo-Li₂S-graphene cathode demonstrates promising application for LIB, where the Mo-Li₂S-graphene//Si? C battery shows a high capacity of 764 mAh g^?1 and outstanding cycle stability.     

Natural rubber nanocomposites with SiC nanoparticles and carbon nanotubes

Single-walled carbon nanotubes (SWNTs) and SiC nanoparticles were dispersed in natural rubber (NR) polymer solution and subsequently evaporated the solvent to prepare NR nanocomposites. Using this technique, nanoparticles can be better dispersed in the NR matrix. The influence of nano-fillers on the mechanical properties of the resulting nanocomposites was quantified.Mechanical test results show an increase in the initial modulus with nanoscale reinforcements for up to 50% strain compared to pure NR. The modulus and strength of natural rubber with 1.5% SiC nanoparticles appear to be superior to those of SWNTs with the same filler content. In addition to mechanical testing, these nanocomposites were studied using the SEM and Raman spectroscopy techniques in order to understand the morphology of the resulting system and the load transfer mechanism, respectively. The Raman spectrum of the SWNT/NR system is characterized by a strong band at 1595 cm⁻¹ (G mode—C-C stretching) and other two bands at 1300 cm⁻¹ (D mode-disorder induced) and 2590 cm⁻¹ (D* band). A shift of the 2590 cm⁻¹ Raman band to the lower wavenumber was observed after subjecting SWNT/NR sample to cyclic stress testing. Ageing SWNT/NR specimen in distilled water for 30 days also provided a similar result. The Raman shift in aged samples indicates internal stress transfer from the natural rubber matrix to the SWNTs implying the existence of bonding at the interface.     

A high performance MQ encoder architecture in JPEG2000

In this paper, a novel architecture for an MQ arithmetic coder with high throughput is proposed. The architecture can process two symbols in parallel. The main characteristics are eight process elements for the prediction of probability interval A, the combination of calculation units for the code register C with the Byteout&Flush procedure, and the use of a dedicated probability estimation table to decrease the internal memory. From FPGA synthesis results, the architecture’s throughput can reach 96.60 M context symbols per second with an internal memory size of 1509 bits, which is comparable to that of other architectures and suitable for chip implementation.