Insights into the efficient water treatment over N-doped carbon nanosheets with layered minerals as template: The role of interfacial electron tunneling and transfer.

Peroxymonosulfate (PMS) oxidation reactions have been extensively studied recently. Due to the high material cost and low catalytic capability, PMS oxidation technology cannot be effectively applied in an industrial water treatment process. In this work, we developed a modification strategy based on enhancing the neglected electron tunneling effect to optimize the intrinsic electron transport process of the catalyst. The 2D nitrogen-doped carbon-based nanosheets with small interlayer spacing were prepared by self-polymerization of dopamine hydrochloride inserted into the natural layered bentonite template. Systematic characterizations confirmed that the smaller layer spacing in the 2D nitride-doped carbon-based nanosheets reduces the depletion layer width. The weak electronic shielding effect derived by the small layer spacing on the material subsurface enhanced the bulk electron tunneling effect. More bulk electrons could be migrated to the catalyst surface to activate PMS molecules. The PMS activation system showed ultrafast oxidation capability to degrade organic pollutants and strong ability to resist interference from environmental matrixes due to the optimized electron transfer process. Furthermore, the developed membrane reactor exhibited strong catalytic stability during the continuous degradation of P-Chlorophenol (CP).

Comparative analysis of codon usage patterns of Plasmodium helical interspersed subtelomeric (PHIST) proteins.

Background: Plasmodium falciparum is a protozoan parasite that causes the most severe form of malaria in humans worldwide, which is predominantly found in sub-Saharan Africa, where it is responsible for the majority of malaria-related deaths. Plasmodium helical interspersed subtelomeric (PHIST) proteins are a family of proteins, with a conserved PHIST domain, which are typically located at the subtelomeric regions of the Plasmodium falciparum chromosomes and play crucial roles in the interaction between the parasite and its human host, such as cytoadherence, immune evasion, and host cell remodeling. However, the specific utilization of synonymous codons by PHIST proteins in Plasmodium falciparum is still unknown. Methods: Codon usage bias (CUB) refers to the unequal usage of synonymous codons during translation, resulting in over- or underrepresentation of certain nucleotide patterns. This imbalance in CUB can impact various cellular processes, including protein expression levels and genetic variation. To investigate this, the CUB of 88 PHIST protein coding sequences (CDSs) from 5 subgroups were analyzed in this study. Results: The results showed that both codon base composition and relative synonymous codon usage (RSCU) analysis identified a higher occurrence of AT-ended codons (AGA and UUA) in PHIST proteins of Plasmodium falciparum. The average effective number of codons (ENC) for these PHIST proteins was 36.69, indicating a weak codon preference among them, as it was greater than 35. Additionally, the correlation analysis among codon base composition (GC1, GC2, GC3, GCs), codon adaptation index (CAI), codon bias index (CBI), frequency of optimal codons (FOP), ENC, general average hydropathicity (GRAVY), aromaticity (AROMO), length of synonymous codons (L_sym), and length of amino acids (L_aa) revealed the influence of base composition and codon usage indices on codon usage bias, with GC1 having a significant impact in this study. Furthermore, the neutrality plot analysis, PR2-bias plot analysis, and ENC-GC3 plot analysis provided additional evidence that natural selection plays a crucial role in determining codon bias in PHIST proteins. Conclusion: In conclusion, this study has enhanced our understanding of the characteristics of codon usage and genetic evolution in PHIST proteins, thereby providing data foundation for further research on antimalarial drugs or vaccines.

Highly efficient broadband white-light emission in two-dimensional semi-conductive hybrid lead chlorides.

White-light emission (WLE) materials based on organic-inorganic hybrid lead halides have drawn considerable attention because of their applications in light-emission equipment. Despite considerable efforts, there is still a lack of two-dimensional (2D) lead-chlorine white-light emitting halides with high photoluminescence quantum efficiency (PLQE). Herein, we report the preparation of a new 2D layered hybrid halide, [DTHPE]Pb4Cl10, which exhibits bright wide-band WLE, a high PLQE of 8.86% and high anti-water stability. To the best of our knowledge, the PLQE of [DTHPE]Pb4Cl10 exceeds that of most 2D lead chlorides. Furthermore, the emission intensity is unchanged even after continuous immersion in water for 7 days. Photoluminescence measurements indicate that the WLE originates from self-trapped excitons. [DTHPE]Pb4Cl10 is a promising visible-blind UV hybrid halide owing to its excellent photoelectric response. [DTHPE]Pb4Cl10 is an effective white-light emitting material for display applications. The coexistence of a high performance visible-blind UV response and high efficiency white-light emission provides attractive possibilities for potential applications in the multifunctional photoelectronic field.

Universal Principle for Large-Scale Production of a High-Quality Two-Dimensional Monolayer via Positive Charge-Driven Exfoliation.

On the basis of the intrinsic characteristics of the layered materials, here we report a universal principle for the production of intact monolayers via layer-by-layer exfoliation from their bulk via positive charge doping. At experimental accessible densities (nc) of ∼1014 cm-2, various multilayer crystals, including graphite, hexagonal boron nitride, transition metal dichalcogenides, MXenes, and black phosphorus, can be exfoliated into the corresponding monolayers through ab initio density functional theory stimulations. The carrier critical thresholds for exfoliating are found to be nearly independent of thickness but dependent on surface size. The universality of positive charge-driven exfoliation originates from the common intrinsic characteristics of electronic structures for layered materials. The positively doped charges that preferentially accumulate near the surface induce interlayer repulsion, leading to layer-by-layer exfoliation when repulsion surpasses interlayer van der Waals force. This strategy may open the possibility of producing diverse high-quality two-dimensional monolayers with a small number of defects toward large-scale manufacturing.

Centimeter-sized lead-free iodide-based hybrid double perovskite single crystals for efficient X-ray photoresponsivity.

Hybrid organic-inorganic lead halide perovskites (HOIPs) possess significant photoelectric characteristics for solar energy conversion, but the presence of lead causes issues for eco-friendly applications. Halide double perovskites represent a green option for application in the optoelectronic field, especially X-ray detection systems. Despite the great efforts, the exploration of large-size lead-free iodide-based hybrid double perovskite single crystals for X-ray detection has been unsuccessful. Herein, we demonstrate that a large single crystal of the 2D (two-dimensional) semiconducting perovskite (C6H16N2)2CuBiI8·0.5H2O can serve as an X-ray detection candidate. A perovskite crystal, as large as 35 × 31 × 3 mm3, was grown using a low-cost, simple cooling solution approach. To the best of our knowledge, this is the first time a centimeter-sized 2D BiCu iodide double perovskite single crystal has been used for X-ray detection. The perovskite crystal exhibited unique properties for X-ray detection, such as a significant X-ray absorption coefficient, considerable µτ product, and low trap density. Moreover, X-ray detection with a sensitivity of 5.51 µC Gyair-1 cm-2 was achieved based on a single crystal. This work opens new ways to explore specially designed organic cations for stabilizing 2D HOIPs that show great potential in optoelectronics.

Strain Effects of Vertical Separation and Horizontal Sliding in Commensurate Two-Dimensional Homojunctions.

Strain, as an economic yet controllable approach for structural modulation, frequently plays a vital role in the preparation and performance optimization of two-dimensional nanomaterials (TNMs). Here, utilizing first-principles simulations, the analysis of energetics shows that the biaxial stretching and compressing could facilitate the vertical separation and horizontal sliding in graphene (Gr/Gr), hexagonal boron nitride (h-BN/h-BN), and molybdenum disulfide (MoS2/MoS2) bilayers. The quantification of electron redistribution between layers confirmed that the shifts of interlayer charge density (ρinter-) and its relative values (Δρinter-) are responsible for the vertical separation and horizontal sliding facilitated by biaxial strain. More effortless horizontal sliding was enabled by a smoother potential energy surface because a smaller Δρinter- can be acquired under compression, whereas more effortless vertical separation followed a more vulnerable surface energy because a lower ρinter- occurs under tensile strain. The vertical and horizontal division of strain effect provides a novel idea for further understanding its pivotal roles in strain engineering of commensurate-contact TNMs, such as mechanical exfoliation and solid lubrication.

A bibliometric-based analysis of the high-value application of Chlorella.

This bibliometric-based review analyses the trends in 1010 published articles (1990 to mid-2018) on the high-value application of Chlorella, and illustrates the evolution and latest tendencies at a global level by the number of publications and their distribution, issuing institutions and countries or regions, the sources and research direction, as well as the core-author and keywords. The results demonstrated that there is a burst in terms of the number of articles, and China, USA, Mexico, and Japan are the dominant countries in this area. The most relevant journals with this subject are Bioresource Technology and Hydrobiology, and the research mainly focuses on marine and freshwater biology, biotechnology and applied microbiology, energy and fuels, food science and technology, and environmental sciences. Overall, bibliometric analysis has shown that Chlorella application research is a very active field, and the future research will be conducted into construction of genetic engineering algae, high-density and low-cost culture systems, efficient harvesting and separation techniques, effective energy conversion, integrated photo-bioreactors, and molecular biology technology. Wastewater treatment, CO2 bio-fixation, biomass production, and biosynthesis of useful substances by cultivating microalgae are promising research fields.

First-principles theory of atomic-scale friction explored by an intuitive charge density fluctuation surface.

Atomic-scale friction theory, and even superlubricity, is inseparable from charge redistribution, but lacks a bridge to establish the potential link between them. Here, we first report a quantized charge density fluctuation surface (CDFS) by assembling silicene/graphene and germanene/graphene heterostructures and their corresponding homogeneous bilayers for DFT calculations. By observing the PES morphology, we see that it exhibits a decrease in friction by more than two orders of magnitude. A crucial physical quantity controlling the friction was found to be the charge density fluctuation during the friction process via analyzing the CDFSs. Such CDFS holds a universal applicability in van der Waals materials, and is recommended to explore the friction cooperating with PES. This will be a new idea for exploring whether friction is related to electrical properties by defining the conversion factor K for a wide series of interactions, including metallic, covalent, and van der Waals bonding. In particular, the same conversion factor K exists for van der Waals bonding, and a mutual identification between the CDFS and PES can be achieved.