Small Methods最新文献

Silicon heterojunction (SHJ) solar cell is an advanced and mature photovoltaic cell. Development of photoelectrochemical (PEC) water splitting devices for hydrogen fuel production using SHJ solar cells is considered as a promising approach to address energy crisis. To achieve this goal, it is necessary to deposit passivation layer and cocatalyst layer on the photoelectrode. However, the development of low-cost and scalable preparation methods for high-quality passivation and cocatalyst layer continues to be a significant challenge. Herein, an efficient passivation layer and hydrogen evolution reaction (HER) catalyst are successfully fabricated via solution processed methods. To improve the HER activity of Ni₃S₂, a Ni₃S₂-based nanoheterostructure of crystalline Ni₃S₂, Ni, and amorphous Y(OH)₃ is constructed. The optimized photocathode exhibits excellent PEC-HER performance, which achieves a saturated photocurrent of -35.5 mA cm^-2 and an applied bias photon-to-current efficiency (ABPE) of 8.4 ± 0.1% under simulated AM1.5G one-sun illumination and more than 120 h of continuous water splitting. This study paves a way for the design and large-scale manufacturing of cost-efficient SHJ photocathode devices.

Spatially resolved transcriptomics (SRT) has become the method of choice for characterising the complexity of biomedical tissue samples. Until recently, scientists were restricted to SRT methods that can profile a limited set of target genes at high spatial resolution or transcriptome-wide but at a low spatial resolution. Through recent developments, there are now methods that offer both subcellular spatial resolution and full transcriptome coverage. However, utilising these new methods' high spatial resolution and gene resolution remains elusive due to several factors, including low detection efficiency and high computational costs. Here, we present Sainsc (Segmentation-free analysis of in situ capture data), which combines a cell-segmentation-free approach with efficient data processing of transcriptome-wide nanometre-resolution spatial data. Sainsc can generate cell-type maps with accurate cell-type assignment at the nanometre scale, together with corresponding maps of the assignment scores that facilitate interpretation of the local confidence of cell-type assignment. We demonstrate its utility and accuracy for different tissues and technologies. Compared to other methods, Sainsc requires lower computational resources and has scalable performance, enabling interactive data exploration. Sainsc is compatible with common data analysis frameworks and is available as open-source software in multiple programming languages.

The presence of oxygen vacancies (V_o) in electrocatalysts plays a significant role in improving the selectivity and activity of CO₂ reduction reaction (CO₂RR). In this study, 1D material with large surface area is utilized to enable uniform V_o formation on the catalyst. 1D structured indium selenoiodide (InSeI) is synthesized and used as an electrocatalyst for the conversion of CO₂ to formate. The electrochemical treatment of InSeI leads to the leaching of Se and I from the catalyst surface and the formation of V_o. The resulting V_o promotes the activity of the CO₂RR, which increases the local pH of the catalyst surface and chemically maintains the oxidized metal sites on the catalyst. Owing to these characteristics, activated In wire exhibited remarkable CO₂RR activity, thereby surpassing 93% FE_formate at 500 mA cm^-2, with a maximum of 97.3% FE_formate at 100 mA cm^-2. Moreover, the catalytic activity remained consistent for over 50 h at 100 mA cm^-2 (FE_formate >88%). Thus, the findings imply that using 1D materials can facilitate the formation of oxygen vacancies on the catalyst surface and improve the selectivity and durability of CO₂RR. This indicates the potential for further research on 1D materials as electrocatalysts.

Hydrogen-terminated 2D-Germanane (2D-GeH), a germanium-based 2D material akin to graphene, is receiving enormous attention owing to its predicted optoelectronic characteristics. However, experimental research of 2D-GeH is still in an early stage, and therefore its real implementation for task-specific applications will depend on the correct development of suitable chemical functionalization methods. Herein, a general and straightforward organometallic (OM) approach is provided for the robust functionalization of 2D-GeH with different 0D noble metal nanoparticles (M-NPs), resulting in 0D/2D M@GeH nanoarchitectonics. As a proof-of-principle, 0D/2D Pt@GeH and Au@GeH nanoarchitectonics have been successfully synthesized, characterized, and explored as unconventional electrocatalysts for boosting energy conversion reactions. While the hydrogen evolution reaction activity was evaluated for Pt@GeH, the oxygen reduction reaction was interrogated for Au@GeH. Interestingly, the implanted catalytic features of M-NPs yielded to 0D/2D M@GeH nanoarchitectonics with enhanced energy conversion activity comparing to pristine 2D-GeH counterpart. This work proves the suitability of 2D-GeH as unconventional substrates to stabilize nobleM-NPs, and the versatility of the OM approach for the custom design of a new family of 0D/2D M@GeH nanoarchitectonics to expand the implementation of monoelemental 2D materials as promising electrocatalysts in energy conversion field and beyond.

Defects are inherent in transition metal dichalcogenides and significantly affect their chemical and physical properties. In this study, surface defect electrochemical nanopatterning is proposed as a promising method to tune in a controlled manner the electronic and functional properties of defective MoS₂ thin films. Using parallel electrochemical nanolithography, MoS₂ thin films are patterned, creating sulphur vacancy-rich active zones alternated with defect-free regions over a centimetre scale area, with sub-micrometre spatial resolution. The patterned films display tailored optical and electronic properties due to the formation of sulphur vacancy-rich areas. Moreover, the effectiveness of defect nanopatterning in tuning functional properties is demonstrated by studying the electrocatalytic activity for the hydrogen evolution reaction.

MXene, a family of 2D transition metal carbides and nitrides, presents promising applications in electrocatalysis. Maximizing its large surface area is key to developing efficient non-noble-metal catalysts for the hydrogen evolution reaction (HER). In this study, oxygen-functionalized Ti₃C₂T_x MXene (Ti₃C₂O_x) is synthesized and deposited gold nanoparticles (Au NPs) onto it, forming a novel composite material, Au-Ti₃C₂O_x. By selectively removing other functional groups, mainly -O functional groups are retained on the surface, directing electron transfer from Au NPs to MXene due to electronic metal-support interaction (EMSI), thereby improving the catalytic activity of the MXene surface. Additionally, the interaction between Au NPs and -O functional groups further enhanced the overall catalytic activity, achieving an overpotential of 62 mV and a Tafel slope of 40.1 mV dec^-1 at a current density of -10 mA cm^-2 in 0.5 m H₂SO₄ solution. Density functional theory calculations and scanning electrochemical microscopy with ≤150 nm resolution confirmed the enhanced catalytic efficiency due to the specific interaction between Au NPs and Ti₃C₂O_x. This work provides a surface modification strategy to fully utilize the MXene surface and enhance the overall catalytic activity of MXene-based catalysts.

Designing effective electrode material is crucial for developing ultra-long lifetime batteries, thereby reducing daily battery costs. Current electrode materials are typically solid or liquid state, with an intermediate colloidal state offering the advantages of fixed redox-active species, akin to solid-state materials, and the absence of rigid atomic structure, akin to liquid-state materials, while avoiding the particle pulverization and uncontrolled migration. Herein, an aqueous Zn||Pluronic F127 (PF127)/ZnI₂ colloid battery is developed utilizing the inherent water molecular control effect of ZnSO₄. In this system, ZnSO₄ in the electrolyte acts as a water molecular valve, regulating the water content within the PF127 polymer to form a PF127 colloid. The resulting aqueous Zn||PF127/ZnI₂ colloid battery exhibits an ultra-long cycling lifetime and compatibility with various simulated and practical operating conditions, highlighting its potential for practical applications. Additionally, this battery design concept offers a platform for constructing ultra-stable aqueous batteries.

Anion exchange membrane water electrolysis (AEMWE) is highly promising for cost-effective green hydrogen production due to its basic operating conditions facilitating the use of non-noble catalysts. While non-noble Ni/Fe-based catalysts are utilized at the anode, its cathode catalyst still requires precious Pt. Due to the high cost of Pt and the sluggish hydrogen evolution reaction (HER) at the cathode in basic conditions, developing alternative catalysts to replace Pt is highly important. Here, a synthesis procedure for a Ru-based catalyst is reported and its high activity toward the HER in alkaline media is demonstrated in both half-cell and single-cell tests. The catalyst is synthesized in a two-step approach. A highly dispersed Ni catalyst is prepared on carbon support in the first step. In the second step, Ru is deposited on its surface using a galvanic displacement reaction. The uniqueness of this method is that Ru is deposited over the entire electrically conductive surface, resulting in an isotropic and homogeneous Ru distribution within the catalyst powder. It is demonstrated that this material remarkably outperforms state-of-the-art Pt/C catalysts in half-cell and single-cell tests. The single cell only requires 1.73 V at 1 A cm^-2 with an overall PGM content of 0.05 mg cm^-2.

In this Perspective, the use of DNA nanotechnology is explored as a powerful tool for studying a family of enzymes known as topoisomerases. These enzymes regulate DNA topology within a living cell and play a major role in the pharmaceutical field, serving as anti-cancer and anti-bacterial targets. This Perspective will provide a short historical overview of the methods employed in studying these enzymes and emphasizing recent advancements in assays using DNA nanotechnology. These innovations have substantially improved accuracy and expanded the understanding of enzyme activity. This perspective will showcase the versatile utility of DNA nanotechnology in advancing scientific knowledge and its application in exploring new drug candidates, particularly in the study of topoisomerase enzymes.

The glycerol oxidation reaction (GOR) for producing high-value-added organic compounds is of great research interest due to its potential in alleviating the energy crisis. Herein, a facile NH₄Cl-assisted electrodeposition strategy is reported to fabricate 3D nano-forest array-like hollow nanostructures. The hierarchical heterojunction by combining phosphorus doping Co(OH)₂ nanosheets with Cu₂S nanotube arrays (P-Co(OH)₂@Cu₂S NTs/CF) is developed to realize the optimization on GOR. The optimized P-Co(OH)₂@Cu₂S NTs/CF catalyst exhibits an exceptional activity with a formate Faradaic efficiency (FE) of 97.40% at a potential of 1.30 V (vs RHE). The experimental results indicate that this unique hollow nano-forest structure, grown on a conductive support, can expose more active sites and facilitate electron transfer, thereby demonstrating excellent GOR performance. This work provides new opportunities for the design of electrocatalysts of high-activity and low-cost hollow heterostructure electrocatalysts for glycerol electrooxidation.