Surface Treatment Strategy Research Articles

Surface treatment processed electron transport layers for efficient Sb2S3 solar cells

Solution-processed Sb2S3 thin films and solar cell devices have recently gained popularity due to their easy procedure and outstanding final device performance. Nevertheless, although the substrate has a significant influence on thefollowing functional films, the effect of the substrate in the Sb-based solar cells appears to have not been adequately examined. In this study, we performed an interesting thioacetamide (TA)-assisted surface treatment strategy on the electron transport layer (ETL) to achieve high-quality development of Sb2S3 thin films and based solar devices. The surface treatment of ETLs resulted in a uniform surface, Zn(OH)2 impurity reduction, and excellent wettability. The above enhanced the growth of Sb2S3 thin films with features like extremely large crystal sizes (∼8 um), more homogeneous and dense film morphology, preferred crystal orientation, reduced oxygen content, and fewer defects, which benefits carrier transport. Finally, a device structure constructed of FTO/TiO2/Zn(O,S)/Sb2S3/Spiro/Au was created, resulting in an almost 30 % increase in efficiency, from 4.05 % to 5.21 %. The proposed approach not only gives new insights into generating higher-quality Sb2S3 thin films and devices, but it also presents new concepts and methods for future high-quality sulfide thin film preparation.

Engineering Triphasic Nanocomposite Coatings on Pretreated Mg Substrates for Biomedical Applications.

Biodegradable polymer-based nanocomposite coatings provide multiple advantages to modulate the corrosion resistance and cytocompatibility of magnesium (Mg) alloys for biomedical applications. Biodegradable poly(glycerol sebacate) (PGS) is a promising candidate used for medical implant applications. In this study, we synthesized a new PGS nanocomposite system consisting of hydroxyapatite (HA) and magnesium oxide (MgO) nanoparticles and developed a spray coating process to produce the PGS nanocomposite layer on pretreated Mg substrates, which improved the coating adhesion at the interface and their cytocompatibility with bone marrow derived mesenchymal stem cells (BMSCs). Prior to the spray coating process of polymer-based nanocomposites, the Mg substrates were pretreated in alkaline solutions to enhance the interfacial adhesion strength of the polymer-based nanocomposite coatings. The addition of HA and MgO nanoparticles (nHA and nMgO) to the PGS matrix, as well as the alkaline pretreatment of the Mg substrates, significantly enhanced the interfacial adhesion strength when compared with the PGS coating on the nontreated Mg control. The average BMSC adhesion densities were higher on the PGS/nHA/nMgO coated Mg than the noncoated Mg controls under direct contact conditions. Moreover, the addition of nHA and nMgO to the PGS matrix and coating the nanocomposite onto Mg substrates increased the average BMSC adhesion density when compared with the PGS/nHA/nMgO coated titanium (Ti) and PGS coated Mg controls under direct contact. Therefore, the spray coating process of PGS/nHA/nMgO nanocomposites on Mg substrates or other biodegradable metal substrates could provide a promising surface treatment strategy for biodegradable implant applications.

Innovative bamboo-plastic composites interfacial compatibility design approach: Self-assembled crosslinked structure of polydopamine with acylated chitin fibers

Achieving interfacial compatibility through sustainable methods is a key objective in natural fiber-plastic composites research, aimed at optimizing mechanical performance. This study introduced an innovative organic bamboo-plastic composite (BPC) interfacial layer, incorporating O-acylated chitin fibers densely coated with polydopamine (PDA) via a mild and facile self-assembly method. Chitin nanofibers were acylated with dodecenylsuccinic anhydride in a deep eutectic solvent in a one-pot process. The resulting BPCs exhibited significantly enhanced mechanical properties, with tensile strength, flexural strength, modulus, and impact strength increased by 73.64 %, 39.19 %, 15.42 %, and 63.57 %, respectively, compared to untreated BPCs. This improvement highlights the effectiveness of tailoring cross-linked networks across heterogeneous interfaces in providing strength, dissipating strain, and promoting interfacial compatibility. Furthermore, these modified BPCs demonstrated enhanced thermal stability, crystallization behavior, and moderate hydrophobicity. This surface treatment strategy offers a distinctive approach to producing high-performance, eco-friendly BPCs, also facilitating the processing and utilization of marine biological resources on a wide scale.

The effect of surface modification strategies on biological activity of titanium implant

The surface morphology of titanium metal is an important factor affecting its hydrophilicity and biocompatibility, and exploring the surface treatment strategy of titanium metal is an important way to improve its biocompatibility . In this study , titanium (TA4) was firstly treated by large particle sand blasting and acid etching (SLA) technology, and then the obtained SLA-TA4 was treated by single surface treatments such as alkali-heat, ultraviolet light and plasma bombardment. According to the experimental results, alkali-heat treatment is the best treatment method to improve and maintain surface hydrophilicity of titanium. Then, the nanowire network morphology of titanium surface and its biological property, formed by further surface treatments on the basis of alkali-heat treatment, were investigated. Through the cell adhesion experiment of mouse embryonic osteoblast cells (MC3T3-E1), the ability of titanium material to support cell adhesion and cell spreading was investigated after different surface treatments. The mechanism of biological activity difference of titanium surface formed by different surface treatments was investigated according to the contact angle, pit depth and roughness of the titanium sheet surface. The results showed that the SLA-TA4 titanium sheet after a treatment of alkali heat for 10 h and ultraviolet irradiation for 1 h has the best biological activity and stability. From the perspective of improving surface bioactivity of medical devices, this study has important reference value for relevant researches on surface treatment of titanium implantable medical devices.

High-Speed Thermo-Compression Sinter-Bonding Properties in Air of a Paste Containing Dendritic Cu Particles Having Oxalate Skins

To enhance the sinter-bonding speed of Cu dendrite particle-based paste, the particles were surface-treated with oxalic acid solution. This treatment transitioned the particle surface from an oxide layer to a CuC 2 O 4 phase, which suppressed the oxidation of Cu until thermal decomposition between 284-315 °C generating Cu nanoparticles. Using the surface-treated Cu dendrite particle-based paste, sinter bonding at 320 °C under 5 MPa pressure in air provided a sufficient shear strength of 23.4 MPa in just 60 s, reaching the maximum of 28.7 MPa after 180 s. The in situ generated Cu nanoparticles from the thermal decomposition of CuC<sub>2</sub>O<sub>4</sub> directly contributed to the very rapid sintering-bonding behavior at 320 °C. However, the bondings at 300 °C and 350 °C showed poorer bonding characteristics than that of before treatment, indicating that the surface treatment strategy for forming CuC<sub>2</sub>O4 skins is effectively implemented by appropriately setting the following sinter-bonding temperature.

Metal–organic framework–derived trimetallic particles encapsulated by ultrathin nitrogen-doped carbon nanosheets on a network of nitrogen-doped carbon nanotubes as bifunctional catalysts for rechargeable zinc–air batteries

Economical oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) bifunctional catalysts with high activity aimed at replacing precious metal catalysts for rechargeable zinc-air batteries (ZABs) must be developed. In this study, a multiple hierarchical-structural material is developed using a facile dielectric barrier discharge (DBD) plasma surface treatment, solvothermal reaction, and high-temperature carbonization strategy. This strategy allows for the construction of nanosheets using nitrogen-doped carbon (NC) material-encapsulated ternary CoNiFe alloy nanoparticles (NPs) on a network of NC nanotubes (NCNTs), denoted as CoNiFe–NC@p–NCNTs. Precisely, the presence of abundant CoNiFe alloy NPs and the formation of M–N–C active sites created by transition metals (cobalt, nickel, and iron) coupled with NC can provide superior OER/ORR bifunctional properties. Moreover, the prepared NC layers with a multilevel pore structure contribute to a larger specific surface area, exposing numerous active sites and enhancing the uniformity of electron and mass movement. The CoNiFe0.08–NC@p–NCNTs show remarkable dual functionality for electrochemical oxygen reactions (ORR half-wave potential of 0.811 V, limiting current density of 5.73 mA cm−2 measured with a rotating disk electrode at a rotation speed of 1600 rpm, and OER overpotential of 351 mV at 10 mA cm−2), which demonstrates similar ORR performance to 20 wt% Pt/C and better OER performance than the commercial RuO2. A liquid ZAB prepared using the proposed material has excellent bifunctionality with an open-circuit voltage of 1.450 V and long-term cycling stability of 230 h@10 mA cm−2.

Functionalized-nanoparticles/silk fibroin coating with anti-adhesive and photothermal capabilities to prevent implant-associated infections

Antibacterial coatings that can firstly prevent bacterial adhesion and then kill the attached bacteria are urgently required for combat of implant-associated infections. However, current surface strategies are limited by complicated preparation, uncontrolled-release of antimicrobials, and low biocompatibility. Here, we developed a dual-functional, antibacterial coating by functionalizing iron oxide nanoparticles (FNP) with polydopamine and polyethylene glycol, and then depositing them with silk fibroin (SF) on a titanium substrate (FNP/SF-Ti). This surface strategy is facile to achieve and widely adapted to any nanoparticles and substrates. In an optimized SF coating density, the FNP/SF-Ti surface reduced bacterial adhesion for more than 100 folds to both Methicillin-resistant Staphylococcus aureus and Escherichia coli to compare with bare Ti surface. Under near-infrared (NIR) light irradiation, the attached bacteria on FNP/SF-Ti surface were totally killed in a photo-controllable way and no biofilm formed subsequently. The in vitro biocompatibility and osteogenic effect of FNP/SF-Ti surface was better than bare Ti and FNP-Ti surface. In a rat sub-cutaneous model, MRSA infections on FNP/SF coated Ti discs were effectively inhibited due to the synergistically effect of anti-adhesive and photothermal performances. In a rat bone-defect model, MRSA-contaminated FNP/SF-Ti rods were disinfected by NIR irradiation after implantation and the osteogenesis on FNP/SF-Ti rods were not affected by MRSA infection. Therefore, the FNP/SF coating is a potential surface treatment strategy to prevent implant-associated infections.

Improved wear and corrosion resistance of alumina alloy by MAO and PECVD

Aluminum alloys, which are vital in various industries, are susceptible to corrosion and wear. Although the micro-arc oxidation (MAO) method addresses these issues, it introduces microporosity, which undermines the integrity of the alloy. In this study, MAO coatings are enriched via plasma-enhanced chemical vapor deposition (PECVD) using hexamethyldisilane, specifically SiCOx and SiOx. The assessment of the mechanical, tribological, and corrosion-resistant characteristics of these composite coatings reveals substantial enhancements in the aluminum alloy properties post-PECVD treatment. Surface morphology observations highlight the reduced pore size and area of the PECVD-coated surfaces, particularly in SiCOx coatings, which are known for their superior gap-filling properties. Scratch tests demonstrate superior adhesion of SiCOx coatings, showed a higher scratch resistance of approximately 17.8 N compared to 15.9 N for SiOx coatings. The wear rate of the SiCOx coating significantly decreased compared to the MAO coating owing to higher hardness, dropping from 3.57 × 10−5 mm3/N·m to 2.04 × 10−5 mm3/N·m. SiCOx-coated surfaces show higher corrosion potential (−0.0078 V) than MAO-only coating (−0.0212 V), indicating enhanced corrosion resistance. These innovative coatings provide an advanced surface treatment strategy and are suitable for a wide range of industrial applications owing to their enhanced surface attributes.

Green mechanochemical Li foil surface reconstruction toward long-life Li–metal pouch cells

A green mechanochemical surface treatment strategy endows practical Li metal pouch cells with excellent electrochemical performance, achieving high energy density, stable cycle performance and high security.

Electrode Surface-Modified Strategy for Improving the Voltage of Aqueous Supercapacitors.

Endowing aqueous supercapacitors (SCs) with high voltage is of great practical significance, but it is restricted by the water decomposition reaction occurring in the electrodes. Here, a novel surface treatment strategy is proposed to inhibit the hydrogen evolution reaction/oxygen evolution reaction at the cathode and anode by forming a passivation layer at the whole electrode surface, which widens the electrochemical stability window of the electrode and working voltage of the aqueous SCs. In addition, the cathode overpotential is increased from -1.3 to -1.48V, and the anode is expanded from 1.42 to 1.59V. Importantly, the aqueous SCs can work stably at 3V operating voltage, enabling the coulombic efficiency and capacitance retention of the optimized SCs is 97% and 96% after 5000 cycles, respectively. This strategy of surface modification provides effective guidance to achieve high-voltage aqueous energy storage devices.

Flexible array of high performance and stable formamidinium-based low-n 2D halide perovskite photodetectors for optical imaging

Metal halide perovskites are attracting increasing attention as photodetectors (PDs) materials due to their excellent photoelectric properties. However, integrating perovskite to realize high-resolution perovskite pixel arrays remains critical to enable practical devices. Herein, we demonstrate a high-responsivity and stable 10 × 10 flexible PDs array based on formamidinium-based quasi-2D Ruddlesden-Popper (BA)2FAPb2I7 (n = 2) (BA= butylammonium, C4H9NH3+) perovskite elements for image sensing. The high-performance (BA)2FAPb2I7 arrays are synthesized on a polyethylene terephthalate (PET) flexible substrate, on a large scale, high quality, and controllable manner by introducing Au nanoparticles to enhance film quality upon the annealing process and recrystallization by applying formamidinium chloride (FACl) post-treatment to reduce perovskite film defects, combined with an innovative SiO2-assisted hydrophilic and hydrophobic surface treatment strategy. The prepared flexible PDs arrays show excellent optoelectronic properties with high responsivity (5.9 A W−1), a detectivity of 8.2 × 1012 Jones, large on/off current ratio (up to 3 × 104), ultimate response speed (12.8 μs/10.1 μs), and wide spectral response range. In addition, the device shows outstanding mechanical stability under severe bending (θ = 120°) and excellent folding durability after thousands of bending cycles. It also exhibits excellent environmental stability with only a slight degradation of photoresponse after 100 days of storage under the ambient environment. Finally, the integrated flexible PDs arrays can be used as an effective visible light image sensor with good spatial resolution, paving a multifunctional and competitive way for future wearable sensors and artificial vision systems. One-sentence summaryLow-dimensional halide perovskite layers pixelized on a polyethylene terephthalate (PET) flexible substrate provide high performance photodetectors.

Electrolytic manganese residue to metal phosphides via ball milling: Enhancing flame retardancy, mechanical properties, and electrical conductivity of epoxy resin

Landfill or open-air stacking of waste electrolytic manganese residue (EMR) poses environmental pollution risks due to the presence of harmful substances. EMR contains SiO2, Al2O3, and Fe2O3, which offer resource utilization and flame retardancy potential. A ball milling-based surface treatment strategy was proposed to modify EMR by incorporating red phosphorus (RP) and graphitic carbon nitride (g-C3N4), resulting in flame retardant EMR-PCN containing metal phosphides. Adding EMR-PCN to epoxy resin (EP) enhanced the flame retardancy of EP, addressing its inherent fire hazard. The EP composite incorporating 5 wt% EMR-PCN (EP/5EMR-PCN) demonstrated a limiting oxygen index of 33.0% and achieves V-0 level in vertical combustion test. Compared to EP, EP/5EMR-PCN showed significant reductions in peak heat release rate (65.3%), total heat release (62.2%), total smoke production (40.7%), and average CO yield (53.8%). Notably, EP/5EMR-PCN achieves a Flame Retardancy Index of 8.37, outperforming most g-C3N4-based flame retardants. Besides, increased hydrophobicity optimized the storage of EMR-PCN. Improved compatibility of EMR-PCN with EP enhanced its mechanical properties. Additionally, volume and surface resistance reductions in EP/5EMR-PCN mitigated static cumulative effects, expanding its application potential.

Surface Miscible Structure Modulation of Li‐Rich Cathodes by Dual Gas Surface Treatment for Super High‐Temperature Electrochemical Performance

AbstractLi‐rich manganese base oxides (LRNCM) are regarded as one of the most promising cathode materials among next‐generation high‐energy density Li‐ion batteries due to the coupling effect of anion and cation redox. However, serious oxygen release, surface structure corrosion, and transformation seriously damage their electrochemical performance and restrict their commercialization process. Herein, a dual gaseous surface treatment strategy with ammonium bicarbonate is designed to reconstruct the surface chemical and structural characteristics of LRNCM. As a result, an enriched oxygen vacancies mixed‐phase surface layer is achieved, which contains spinel phase and cation‐disordered phase. The integration of the surface mixed phase effectively inhibits irreversible oxygen loss, prevents electrode corrosion, and promotes fast Li‐ion diffusion. Accordingly, the modified cathode exhibits excellent specific capacity, high‐rate capability, and superior cycle life at both 25 and 60 °C. Particularly at high temperatures, it achieves impressive performance: initial coulombic efficiency (82.0 vs 74.4%), cycling stability at 1 C after 100 cycles (92.6 vs 83.8%), and rate performance at 5 C (56.0 vs 48.7%). This reconfiguration approach introduces a novel idea for the design of cathode material interfaces.

Gorgeous turn-back: Rough surface treatment strategy induces Cu-C and N-C active moieties for bifunctional oxygen electrocatalysis

Fabricating inexpensive and quality bifunctional catalysts for catalyzing oxygen reduction/evolution reactions (ORR/OER) is urgent for the wide application of zinc-air batteries (ZAB). Herein, a bifunctional catalyst, nitrogen-doped graphdiyne (Cu NPs/NGDY) with Cu-C and N-C active moieties, is fabricated through pyrolysis. Cu NPs/NGDY exhibits excellent catalytic performance towards ORR (E1/2 = 0.86 V), stability of 86.5% current retention for 24 h and OER (Ej=10 = 360 mV). Experimental results and theoretical calculations reveal the vital role of Cu-C and nitrogen doping in regulating electrocatalytic activity. Assembled with Cu NPs/NGDY as electrocatalyst, both the liquid-state and flexible ZABs exhibit high power density and barely changed gap between discharge and charge voltage with robust stability, demonstrating tremendous potential in the field of wearable-related equipment. This work develops a simple strategy to fabricate GDY -based bifunctional catalyst.

In Situ Reconstruction of Hole‐Selective Perovskite Heterojunction with Graded Energetics Toward Highly Efficient and Stable Solar Cells

AbstractPerovskite solar cells (PSCs) have demonstrated a high power conversion efficiency, however, the large energy loss due to non‐radiative recombination is the main challenge for further performance enhancement. Here, a surface treatment strategy is developed by heat‐induced decomposition of a thin interlayer 2,7‐Naphthaleneditriflate (NAP) to in situ reconstruct perovskite energetics. It is verified that the reconstructed perovskite surface energetics match better with the upper hole transport layer compared to the intrinsic condition. Spontaneous generation of n/n− homojunctions between the perovskite film bulk and the surface region promotes hole extraction, enhancing built‐in electric field, and thus significantly suppresses charge recombination at such perovskite hole‐selective heterojunctions. Moreover, the surface decomposed fluorine‐rich complexes passivate the defects and improve the crystallinity of the perovskite film. These advantages are confirmed by a remarkably improved efficiency from 20.52% for the control device to 23.37% for the treated one with excellent stability. The work provides a promising approach of in situ reconstructing perovskite surface and interface for the design of highly efficient and stable PSCs.

Sequential treatment process in a rotary container polishing machine with periodic workpiece location changes in working abrasives areas

This paper presents the process of a 3-step machining process involving pre-treatment, smoothing and polishing, placing the workpiece in different energy levels of the working load in a rotary-cascade container smoother, by moving it towards the radial direction of the working chamber of the smoother. Studies show the ability to control the course of pre-treatment, smoothing and finishing intensity, both in terms of process parameters and treatment time. Such a structure of the machining process, it also allows you to influence the structure geometry of the machined surfaces in successive stages of machining, and consequently on the final quality. The proposed organization and structure of the process allows for the creation of a new one surface treatment strategy.

Facile surface treatment strategy to generate dense lysozyme layer on ultra-high molecular weight polyethylene enabling inhibition of bacterial biofilm formation

Medical plastics such as those found in endotracheal tubes are widely used in intensive care units for the treatment of critically ill patients. Although commonplace in hospital environment, these catheters are at a high risk of bacterial contamination and have been found responsible for numerous health-care-associated infections. Antimicrobial coatings that can prevent harmful bacterial growth are required to reduce the occurrence of such infections. In this study, we introduce a facile surface treatment strategy that could form antimicrobial coatings on the surface of average medical plastics. The strategy involves treatment of activated surfaces with lysozyme, a natural antimicrobial enzyme presenting in human lacrimal gland secretions which is widely used for wound healing. Using ultra-high molecular weight polyethylene (UHMWPE) as the representative surface, oxygen/argon plasma treatment for 3 min led to the increase of surface roughness and the generation of negatively charged groups, with the zeta potential measured as −94.5 mV at pH 7. The activated surface could accommodate lysozyme with a density of up to 0.3 nmol/cm2 through electrostatic interaction. Antimicrobial activity of the resulting surface (UHMWPE@Lyz) was characterized with Escherichia coli and Pseudomonas sp. strains, and the treated surface significantly inhibited the bacterial colonization and the formation of biofilm compared to the untreated UHMWPE. This method of constructing an effective lysozyme-based antimicrobial coating is a generally applicable, simple and fast process for surface treatment with no adverse solvent and wastes involved.

Surface passivation of intensely luminescent all-inorganic nanocrystals and their direct optical patterning

All-inorganic nanocrystals (NCs) are of great importance in a range of electronic devices. However, current all-inorganic NCs suffer from limitations in their optical properties, such as low fluorescence efficiencies. Here, we develop a general surface treatment strategy to obtain intensely luminescent all-inorganic NCs (ILANs) by using designed metal salts with noncoordinating anions that play a dual role in the surface treatment process: (i) removing the original organic ligands and (ii) binding to unpassivated Lewis basic sites to preserve the photoluminescent (PL) properties of the NCs. The absolute photoluminescence quantum yields (PLQYs) of red-emitting CdSe/ZnS NCs, green-emitting CdSe/CdZnSeS/ZnS NCs and blue-emitting CdZnS/ZnS NCs in polar solvents are 97%, 80% and 72%, respectively. Further study reveals that the passivated Lewis basic sites of ILANs by metal cations boost the efficiency of radiative recombination of electron-hole pairs. While the passivation of Lewis basic sites leads to a high PLQY of ILANs, the exposed Lewis acidic sites provide the possibility for in situ tuning of the functions of NCs, creating opportunities for direct optical patterning of functional NCs with high resolution.

Rejuvenation of aged graphite anodes from spent lithium-ion batteries via a facile surface treatment strategy.

In this study, we present a facile formic acid treatment to rejuvenate aged graphite anodes from spent lithium-ion batteries (LIBs) without damaging the electrode structure. This method effectively removes the interfacial blocking layer, improving capacity and rate performance. Our approach contributes to sustainable battery recycling strategies for spent graphite anodes in LIBs.

Efficient inverted CsPbI3 inorganic perovskite solar cells achieved by facile surface treatment with ethanolamine.

The all-inorganic CsPbI3 perovskite presents promising prospects due to its suitable band gap and nonvolatile nature, while serious nonradiative recombination and unmatched energy level alignment hinder its further developments. Here, a facile and effective surface treatment strategy is proposed to modify the CsPbI3 surface with ethanolamine, leading to significantly reduced defects, and ameliorated band alignment and morphology. Consequently, a champion power conversion efficiency of 18.41% with improved stability is achieved for the inverted CsPbI3 solar cells.