Abundant Oxygen-containing Groups Research Articles

Preparation of artificial humic acid from corn straw and its high-efficiency adsorption on norfloxacin

In this study, the biomass artificial humic acid (AHA) with efficient adsorption performance for norfloxacin (NOR) was prepared by ultrasonic-assisted acid-alkaline combined hydrothermal method with corn straw as raw material. Characterization analysis showed that AHA was a typical amorphous structure, and the oxygen content of AHA prepared by ultrasonic-assisted hydrothermal method was obviously improved compared with that without ultrasonic-assisted method. The saturated adsorption capacity of AHA was 551.53 mg/g, which was higher than that of other reported materials, such high-efficiency adsorption is due to the abundant oxygen-containing groups (–OH, –C=O, etc.) in AHA, which were functional groups that can be π-π stacked, hydrogen bonded and electrostatically bonded with NOR. It had good selective adsorption for NOR, with less interference from acidity of environmental water, coexisting inorganic ions and common antibiotics. When it was applied to adsorb NOR with concentration of 10.0 mg/L in simulated water prepared by environmental water, the highest removal rate was 91%, which indicated that AHA could not only remove all the NOR in the polluted water with complex components at the highest concentration of 630 μg/L, but also its adsorption capacity far exceeded the pollution amount. The research had important practical significance in realizing the recycling of agricultural wastes and the removal of environmental pollution.

Multifunctional HxMoO3-y-MoO2/Carbon Composite Particles for Water Remediation.

Solving a scarcity of freshwater resources is an urgent global challenge by a safe and sustainable approach using renewable energy. We demonstrate the multifunctional catalyst of HxMoO3-y-MoO2/carbon composite particles toward highly efficient water remediation. A one-step mechanochemical reaction successfully upgraded the composites from commercially available MoO3-polypropylene (PP) powders without introducing hydrogen gas. The composite particles exhibited broad light absorption in the UV-visible (Vis)-near-infrared (NIR) region (200-2000 nm), with an optical band-gap narrowing to 1.03 eV. The plasmonic properties of HxMoO3-y-MoO2 allowed a fast water evaporation rate (3.29 kg m-2 h-1) with a photothermal conversion efficiency of 88.8%. In addition, the HxMoO3-y-MoO2 heterojunction dominated wide-spectrum activity under Vis and NIR light irradiation, up to 3 orders of magnitude higher than pristine MoO3 in the photocatalytic degradation of azo-dye pollutants. Furthermore, the byproduct carbon with abundant oxygen-containing groups efficiently eliminated water pollutants as a Brønsted acid catalyst and performed exceptional adsorption capacities of heavy metal ions in the dark.

Regulating Li+ transport behavior by cross-scale synergistic rectification strategy for dendrite-free and high area capacity polymeric all-solid-state lithium batteries

The inability to effectively inhibit the lithium (Li) dendrite growth is identified as the real culprit hindering the practical application of polyethylene oxide (PEO)-based electrolytes. Herein, a novel PEO composite electrolyte with ion rectifier is developed based on the cross-scale synergistic rectification strategy. At the micro-scale, the array structure of the ion rectifier suppresses the growth of PEO crystals and their distribution in the non-ionic conduction direction through space confinement, alleviating ion-migration crosstalk and enabling polymer chain rectification. Furthermore, the matrix contains abundant copper ions and oxygen-containing groups that inhibit anion conduction and accelerate Li+ migration at the nanoscale, respectively, to achieve ion flow rectification. Implementing this strategy results in a uniform, fast, and stable Li+ migration/diffusion behavior from the electrolyte to anode interface. The critical current density of the PEO electrolyte is increased to 2.5 mA cm−2, indicating a significant improvement in dendrite growth inhibition. Impressively, the composite electrolytes exhibit long-term stability (>4000 h at 0.2 mA cm−2) and ultra-high current-density tolerance (>200 h at 1 mA cm−2). Moreover, the composite electrolytes enable stable cycling of high-area-capacity (3.11 mAh cm−2, 20 mg cm−2) LiFePO4/Li pouch cells, highlighting the importance of this strategy for the practical application of PEO electrolytes.

Tailored GO nanosheets for porous framework to high CO2 adsorption

The 2D graphene oxide (GO) is promising for CO2 adsorption, benefitting from its theoretically high specific surface area and abundant oxygen-containing groups. However, the GO nanosheets aggregation renders the loss of CO2 adsorption site, reducing the CO2 adsorption capability. To tackle this issue, we propose of tailoring physical and chemical structures of the GO nanosheet by etching and oxidation, which concurrently enhance the specific surface area and oxygen-containing functional groups. The etching step creates additional in-plane nanopores in the GO nanosheet and uncovers the inaccessible sites on the GO nanosheet. The oxidation step produces more oxygen-containing groups, i.e., active sites, to intensify the CO2 adsorption of GO nanosheets. Resultantly, through enhancing pore volume and interaction between CO2 and oxygenic functional group, the adsorption capacity of CO2 is promoted. As such, the CO2 adsorption capability of GO nanosheets is significantly enhanced. The optimized oxidized porous GO nanosheets are employed for CO2 adsorption after Ca2+ crosslinking, which realizes a high CO2 adsorption capability of 2.5 mmol/g at 298 K, 1 bar. Together with its prominent running stability, the fabricated porous GO-based adsorbents show great potential for CO2 capture to mitigate the current greenhouse gas dilemma.

Interface Modulation of 2D Superlattice Heterostructures with Oxygen-enriched Sites and Dissolution Restraint for Effective Rare-earth Elements Extraction

Effective recovery of rare earth elements from wastewater is crucial for the modern industry, as well as for protecting the human health and ecosystem. Nevertheless, it is still challenging to realize efficient and selective low-concentration rare earth extraction in systems containing high levels competing metal ions. Here, we report on the fabrication of two-dimensional superlattice heterostructures (VOGO-x) through the alternating restacking of VOPO4 nanosheets and GO-PDDA nanosheets via electrostatic self-assembly. The meticulously organized molecular scale of superlattice heterostructures enable the full exposure of accessible adsorption sites and facilitate the transport of rare earth ions, meanwhile the abundant oxygen-containing phosphate groups within the interlayer can realize selective rare earth ions extraction. Furthermore, the tunable interlayer interaction can promote structure stability to prevent dissolution. Consequently, VOGO-11 possesses excellent rare earth adsorption performance, with a saturated adsorption capacity (Nd(III) 631.52 mg/g, Dy(III) 689.48 mg/g, Lu(III) 716.06 mg/g), high utilization rate of adsorption sites and short adsorption equilibrium time of simply 10 min in the REE aqueous solution. Furthermore, VOGO-11 exhibits outstanding selective rare earth adsorption ability over a wide range of metal ions in the low-concentration simulated wastewater and actual leaching tailings. These results demonstrate the material’s promising potential in capturing rare earth ions and pave the way to the development of two-dimensional superlattice heterostructures through interface modulation for effective rare earth extraction.

A novel cobalt-iron bimetallic hydrochar for the degradation of triclosan in the aqueous solution: performance, reusability, and synergistic degradation mechanism

Low activation performance is a critical issue limiting the practical application of low-cost biochar in the advanced oxidation. Given the high potential of transition metals in the persulfate activation process and abundant oxygen-containing groups of hydrochar, hydrochar derived from cobalt (Co)-modified iron (Fe)-enriched sludge was synthesized and its performance and activation mechanism for the degradation of triclosan were investigated. Co modification significantly altered the morphology of hydrochar, and the increased Co–Fe mass ratios transformed hydrochar from granular to rose-shaped lamellar and then to helical sheet structures. Specific surface area, defect degree, and oxygen-containing groups of hydrochar increased with increasing cobalt-iron mass ratios. The highest removal of triclosan was up to 98% in the hydrochar/peroxymonosulfate (PMS) system under a wide range of pHs (3–10) and still remained higher than 90% after four cycles. Both Radical (mainly hydroxyl radical) and nonradical pathways (singlet oxygen and electron transfer) were evidenced to play roles in the triclosan removal. Fe3+ promoted the regeneration of Co2+ and realized the efficient circulation of Co3+/Co2+. A ternary system consisting of electron donor (triclosan)-electron mediator (hydrochar)-electron acceptor (PMS) provided channels for electron transfer. No measurable Co and Fe were released during the reaction, and the toxicity of degradation intermediates was lower than that of triclosan. Beside triclosan, rhodamine B, bisphenol A, sulfamethoxazole, and phenol were also almost degraded completely in this oxidation system. This study provides a promising way for the enhancement of catalytic activity of carbonaceous material.

Graphene oxide intercalated Alk-MXene adsorbents for efficient removal of Malachite green and Congo red from aqueous solutions

Currently, adsorbents with high adsorption performance for eliminating pollutants from discharged wastewater have received many researchers’ attention. To this aim, a novel AMXGO absorbent was fabricated by intercalating graphene oxide (GO) into alkalized MXene (Alk-MXene) layer which exhibited high efficacy for the removal of cationic Malachite Green (MG) and anionic Congo Red (CR). Analysis of FTIR, XRD, SEM and TG presented that AMXGO absorbent have a typical three-dimensional layer by layer structure and abundant oxygen-containing groups and its thermal stability was remarkably improved. BET results elucidated that AMXGO1 adsorbent has larger specific surface area and pore volume (16.686 m2 g−1, 0.04733 cm3 g−1) as compared to Alk-MXene (4.729 m2 g−1, 0.02522 cm3 g−1). A dependence of adsorption performance on mass ratio between Alk-MXene and GO, initial dye concentration, contact time, temperature and pH was revealed. Maximum adsorption capacity of MG (1111.6 mg/g) and CR (1133.7 mg/g) were particularly found for AMXGO1 absorbent with a mass ratio of 3:1 and its removal for both dyes were higher than 92%. The adsorption process of AMXGO1 adsorbent for both MG and CR complies with pseudo-second-order kinetic model and Freundlich isotherm model. In addition, adsorption mechanism was explored that synergism effects as electrostatic attraction, π-π conjugates, intercalation adsorption and pore filling were the main driving force for the high adsorption performance of dye. Therefore, AMXGO adsorbent has a potential application prospect in the purification of dye wastewater.

Hydrophobic modification of walnut shell biomass-derived porous carbon for the adsorption of VOCs at high humidity

Volatile organic compounds (VOCs) often contain water vapor in their exhaust emissions, resulting in the deterioration of the adsorption capacity of activated carbon (AC). A hydrophobic walnut shell biomass-derived AC using polytetrafluoroethylene (PTFE) and polydimethylsiloxane-coated SiO2 (PDMS/SiO2) was developed to improve the selectivity of VOCs under high humidity conditions. These modified ACs were systematically characterized, and dynamic adsorption behaviors of VOCs such as toluene, acetone and their mixtures at the relative humidity (RH) between 0 and 90 % were conducted. The results showed that walnut shell biomass-derived AC has large specific surface area (1853 m2/g) and total pore volume (1.27 cm3/g), strong hydrophilicity (water contact angle of 6.3°), abundant oxygen-containing groups (OH, CO, CO) and aromatic rings. The coating of PDMS/SiO2-PTFE reduces the surface area and total pore volume of AC, but it creates a double-layer rough structure on the AC surface and introduces CF and SiOSi hydrophobic groups, which achieves a water contact angle of 152.8° for 25PSP/AC. The Yoon-Nelson model is suitable to describe the dynamic adsorption process of single- toluene or acetone under dry/humid condition but not suitable for their mixtures. At RH 90 %, PDMS/SiO2-PTFE modified AC significantly increases the adsorption capacity of toluene but is not obviously improved for acetone, which is due to the different polarity of toluene and acetone. PDMS/SiO2-PTFE films on AC have good thermal stability before 500 °C and the hydrophobicity does not change after multi-regeneration at 200 °C. Therefore, PDMS/SiO2-PTFE modified AC has shown great potential as adsorbent to remove the toluene from the humid condition.

Integrated preparation of functional lignin nanoparticles and levulinic acid directly from the pre-hydrolysis liquor of poplar wood

The pre-hydrolysis liquor (PHL) produced during pulp dissolution and biomass refining is mainly composed of hemicellulose and lignin, and it is a potential source for production of value-added materials and platform chemicals; however, their utilization has been a serious challenge. In this study, we proposed a green and simple strategy to simultaneously prepare size-controlled functional lignin nanoparticles (LNPs) and levulinic acid (LA) from PHL as the raw material. The as-prepared LNPs exhibited remarkable stability thanks to the presence of saccharides with abundant oxygen-containing groups and surface charges, which prevented aggregation and maintained long-term storage stability. Trace amounts of the LNPs (≤ 0.2 wt%) could stabilize various Pickering emulsions, even with oil-to-water ratios as high as 5:5 (v/v). Subsequently, the remaining PHL was directly used to produce LA without adding a catalyst; under optimal conditions (160 °C and 1 h), the yield of LA was 56.3 % based on the dry saccharide content in the raw PHL. More importantly, p-toluenesulfonic acid (p-TsOH), the only reactive reagent used during the entire preparation process, including the two preparation steps of the LNPs and LA, was reusable, and the recovery rate was >70 % after five cycles. Overall, this green and simple strategy effectively and comprehensively utilized the PHL and showed potential for producing biobased nanomaterials and platform chemicals.

Upcycling of waste poly(lactic acid) into crumped carbon nanosheet towards high-performance interfacial solar-driven evaporation

The controllable carbonization of waste plastics into functional carbon nanomaterials towards environmental remediation, energy conversion and storage has received widespread attention. However, there are few studies on the carbonization of poly(lactic acid) (PLA) into porous carbon. Herein, the controlled carbonization of PLA into crumped carbon nanosheet (CCN) is reported. Firstly, recycled PLA bags are converted into magnesium-based metal-organic framework (Mg-MOF) through the combined strategy of mechanochemical milling and solution mixing, and then Mg-MOF is transformed into CCN through the metal-organic framework (MOF)-assisted carbonization strategy. CCN exhibits merits of abundant nanopores and oxygen-containing groups. As a result, the CCN-derived evaporator holds good light absorptivity, low evaporation enthalpy, and good light-to-thermal conversion ability. Furthermore, the CCN-derived solar evaporator achieves a high evaporation rate (2.70 kg m−2 h−1) at 1 kW m−2 irradiation, along with good long-term stability, which surpasses many recent advanced solar evaporators. Noteworthy, when wastewater, lake water, seawater, tetracycline solution, and dye-polluted water are used, the CCN-based evaporator remains high performance in freshwater production. Importantly, an outdoor CCN-based device is constructed, which realizes the freshwater production of 6.3 kg m−2. The collected freshwater can cultivate well mung bean sprouts under natural condition. This work not only provides a new "turning-waste-into-treasure" method for the recycling of waste PLA, but also offers a novel strategy for the preparation of low-cost, functional carbon materials for diverse applications.

The adsorption and release mechanism of different aged microplastics toward Hg(II) via batch experiment and the deep learning method

Aged microplastics are ubiquitous in the aquatic environment, which inevitably accumulate metals, and then alter their migration. Whereas, the synergistic behavior and effect of microplastics and Hg(II) were rarely reported. In this context, the adsorptive behavior of Hg(II) by pristine/aged microplastics involving polystyrene, polyethylene, polylactic acid, and tire microplastics were investigated via kinetic (pseudo-first and second-order dynamics, the internal diffusion model), Langmuir, and Freundlich isothermal models; the adsorption and desorption behavior was also explored under different conditions. Microplastics aged by ozone exhibited a rougher surface attached with abundant oxygen-containing groups to enhance hydrophilicity and negative surface charge, those promoted adsorption capacity of 4–20 times increment compared with the pristine microplastics. The process (except for aged tire microplastics) was dominated by a monolayer chemical reaction, which was significantly impacted by pH, salinity, fulvic acid, and co-existing ions. Furthermore, the adsorbed Hg(II) could be effectively eluted in 0.04% HCl, simulated gastric liquids, and seawater with a maximum desorption amount of 23.26 mg/g. An artificial neural network model was used to predict the performance of microplastics in complex media and accurately capture the main influencing factors and their contributions. This finding revealed that aged microplastics had the affinity to trap Hg(II) from freshwater, whereafter it released the Hg(II) once transported into the acidic medium, the organism's gastrointestinal system, or the estuary area. These indicated that aged microplastics could be the sink or the source of Hg(II) depending on the surrounding environment, meaning that aged microplastics could be the vital carrier to Hg(II).

Ozone-based in-situ reactive extrusion for rapid functionalisation and degradation of low density polyethylene

Improving the hydrophilicity of low density polyethylene (LDPE) expends its use in blends. LDPE melt was rapidly functionalised and degraded by ozone in twin-screw extruder by varying extrusion times from one to seven and temperatures from 160 °C to 240 °C. Abundant oxygen-containing groups, such as carbonyl group (CO) at 1718 cm−1, hydroxyl group (-OH) at 3400 cm−1 and aldehyde group (-CHO) at 1740 cm−1, were generated into ozone treated PE, resulting in improved hydrophilicity. At 200 °C, ozone treated PE exhibited a high melt flow index (21.5 g/10 min) and low complex viscosity modulus due to molecular degradation. Nevertheless, cross-linking occurred at a higher temperature of 240 °C. A higher crystal peak temperature of ozone treated PE at 200 °C was attributed to the introduction of oxygen atoms. The poor thermal stability of ozone treated PE was evidenced by a lower initial decomposition temperature. The oxidation induction time of ozone treated PE at 200 °C declined from 32 min for one extrusion to 12 min for seven extrusions demonstrating a vulnerability of ageing. Increasing the extrusion times gradually enhanced the tensile modulus of the ozone treated PE at 200 °C, while raising the treatment temperature had no effect on the tensile properties. Rapid functionalisation and degradation of LDPE were successfully achieved using ozone in reactive extrusion, thus broadening the applications of ozone treated PE in composites.

Nitrogen-doped lychee-like saccharide-based carbon microspheres with high-performance microwave absorption

The reasonable design of multiple interfaces and heteroatom doping can substantially improve the wave-absorbing performance of electromagnetic wave (EMW) absorbing materials. As the carbon source of biomass, the carbon material with abundant oxygen-containing groups on the surface can be obtained by hydrothermal method, which is conducive to modification and design of the morphology. In addition, N-hydroxymethyl acrylamide contains rich N atoms and has good water solubility, which can be well combined with sugar to prepare high-performance wave-absorbing materials. In this study, D-xylose and glucose were used as carbon sources, water was used as solvent, N-hydroxymethyl acrylamide was added, and nitrogen-doped lychee-like saccharide-based carbon microspheres (LSCMs) were obtained by hydrothermal synthesis and high-temperature carbonization. LSCMs-2 with good EMW attenuation capability and impedance matching performance was obtained by controlling the proportion of different raw materials. Under the optimal filling conditions, the EMW absorber is only 2 mm thick and achieves a minimum reflection loss (RL min) of −47.44 dB at 13.84 GHz with an effective absorption bandwidth (EAB) of 12.24–17.36 GHz (5.12 GHz). The excellent EMW attenuation performance is mainly attributed to dipole polarization and interface polarization in the LSCMs. This research offers a new green synthesis route for the preparation of EMW absorbers with wider bandwidth, thinner thickness and better absorption performance.

A carbon quantum dot based on tetramethyl substituted cucurbit[6]uril and 2,7-dihydroxynaphthalene: Selective detection of Fe3+, ClO−and I−

Carbon quantum dots have attracted much attention as novel nanomaterials. In this study, TMeQ[6]-CQDs were synthesized by a conventional hydrothermal method using symmetric tetramethyl-substituted cucurbit[6]uril (TMeQ[6]) and 2,7-dihydroxynaphthalene (DHN) as carbon precursors, which characterized by 1H NMR, UV–vis, FL, SEM, FTIR, and XPS. Futhermore, the crystal structure was determined using Single crystal X-ray crystallography, demonstrating the formation of TMeQ[6]-based supramolecular assemblies (TMeQ[6]-DHN-[CdCl4]2−). The prepared TMeQ[6]-CQDs have abundant oxygen-containing groups with excellent water-solubility and fluorescence properties. Subsequently, using the obtained TMeQ[6]-CQDs, a universal fluorescent probe was prepared for detecting and recognizing Fe3+, I−, and ClO−. In the presence of Fe3+and I− ions, the fluorescent CQDs are quenched. Interestingly, the fluorescence spectral line undergoes a red-shift when interacting with ClO−. The detection limits were 0.41 μM, 3.71 μM and 0.10 μM.

A value product after the hydrothermal treatment of sludge: Carbon quantum dots and its application

Carbon quantum dots (CQDs) are highly promising fluorescent nanomaterials with a wide range of applications. This study presented a novel, clean, hydrothermal carbonization (HTC) method for synthesizing fluorescent CQDs from sludge. A response surface design method was employed to optimize synthesis conditions, resulting in CQDs with excellent fluorescence properties. They were excited at 320 nm and emitted blue fluorescence at 450 nm under UV light. A mechanism for the formation of CQDs from sludge during HTC was proposed and revealed that the CQDs had an aromatic polymer structure with abundant oxygen-containing groups. X-ray photoelectron spectroscopy confirmed N and Fe doping of CQDs, which significantly improved their fluorescence properties. Additionally, a fluorescence quenching analysis showed that the CQDs selectively detected Pb2+ in the aqueous phase, indicating their potential application in Pb2+ detection. The photoinduced electron transfer (PET) arising from amino groups and other reductive functional groups has been shown to align with the quenching mechanism during the detection of Pb2+ by CQDs. This study provided a cost-effective and scalable approach that could be used to produce CQDs for the in situ detection of Pb2+ in wastewater.

Ultrasensitive electrochemical sensing of catechol and hydroquinone via single-atom nanozyme anchored on MOF-derived porous carbon

Single-atom nanozymes (SANs) can significantly enhance the sensitivity and selectivity of electrochemical sensing platforms due to the homogeneity of their active sites, full atom utilization, and high catalytic activity. In this study, we demonstrate the synthesis and characterization of a high-density Co-based single-atom nanozyme anchored on activated MOF-derived porous carbon (Co-AcNC-3) via a cascade anchoring strategy for ultrasensitive, simultaneous electrochemical detection of catechol (CC) and hydroquinone (HQ). The Co-AcNC-3 displays a large specific surface area, high defectivity, and abundant oxygen-containing groups, with Co atoms being atomically dispersed throughout the carbon support via Co–N bonds. The Co-AcNC-3 biosensor exhibits superior electrochemical signals for CC and HQ, with linear ranges of 4.0 μM–300.0 μM. and detection limits of 0.072 μM and 0.034 μM, respectively. Moreover, the Co-AcNC-3 biosensor has shown excellent performance in accurately detecting CC and HQ in actual samples. Our findings highlight the potential of the proposed Co-AcNC-3 biosensor as a reliable and promising sensing platform for determining CC and HQ.

3D nano-structured sepiolite dynamic membranes for enhanced ultrafiltration treatment and membrane fouling mitigation

The construction of replaceable dynamic membranes (DMs) on membrane surfaces is a promising strategy to effectively mitigate membrane fouling. Nevertheless, the efficiency of DMs in mitigating membrane fouling remains low due to the lack of microstructural configurations. Herein, we report a natural sepiolite (SEP) DM with a three-dimensional (3D) network structure for mitigating PES ultrafiltration (UF) membrane fouling. The abundant oxygen-containing groups on the surface of SEP nanofibers endowed SEP DM with good organic adsorption capacity, hindering the migration of contaminants such as humic acid (HA) and bovine serum albumin (BSA). Owing to the porous 3D network structure, SEP DM prevented the formation of a dense filter cake layer, which effectively mitigated the sharp rise in membrane resistance when filtering ideal HA and BSA solutions. For the actual secondary wastewater, SEP DM improved the removal of UV254 and DOC by 29.8% and 22.5%, respectively, over the pristine PES membrane. The decrease in membrane-specific flux was mitigated by about 20%. Notably, the dynamic nature of SEP DM allowed the contaminated DM layer to be replaced by hydraulic cleaning, resulting in 99% flux recovery (only 89% for the pristine PES membrane). These findings are beneficial in providing new ideas for the mitigation and control of UF membranes.

Weldability improvement of immiscible polycarbonate/GFRP by femtosecond laser surface treatment

Poor miscibility is an important reason for the non-weldable performance of most dissimilar polymers and their composites, and traditional surface treatments cannot effectively improve the weldability of dissimilar polymers. Therefore, the non-weldability of dissimilar polymers is one of the important factors that limit the application of polymers and their composites. We proposed a surface modification scheme of laser ablation or etching to improve the weldability of immiscible polymers effectively. Experimental studies on femtosecond ultraviolet (UV) laser ablation/etching, mid-infrared laser transmission welding (LTW), and related characterization and mechanical tests were carried out. The experimental results showed that laser ablation induced the deposition of abundant polar oxygen-containing groups on the surface of polycarbonate (PC), which improved the miscibility of PC and polyamide 66 with a glass fibre volume ratio of 30% (PA66GF30) and reduced the weak boundary layer (WBL), thereby improving their chemical bonding performance. Using the compatibilization mechanism induced by laser ablation, the bonding strength of the PC/PA66GF30 joint obtained by LTW was 13.7 MPa, which was much higher than that of the untreated joint (1.4 MPa). However, the grooves generated by laser etching could induce macro-anchoring effect of the hybrid joint. Based on the compatibilization mechanism and macro-anchoring effect, with the selection of appropriate welding power and etching parameters, the bonding strength of the PC/PA66GF30 joint was further increased to 29.7 MPa. This work has demonstrated the feasibility of laser surface treatment (especially etching) to significantly improve the welding strength of immiscible polymers and their composites.

Facile Synthesis of Oxidized Boron Nanosheets for Chemo- and Biosensing.

As recently emerging nanomaterials, boron nanosheets (BNSs) have attracted more and more attention in various fields such as supercapacitors, photodetectors, bioimaging, and electrocatalysis due to their advantages of good biological compatibility, environmental friendliness, and good electro-optical properties. However, the study and application of BNSs in chemical and biological sensing are still in the infant stage, mainly due to the requirement of complicated, high-cost, and time-consuming preparation strategies. In this work, a new class of BNSs, namely oxidized-BNSs (i.e., ox-BNSs), were easily and rapidly synthesized by chemically treating boron powder with diluted HNO3 in a very short time (less than 15 min). The composition, morphology, optical property, and peroxidase mimetic activity of obtained ox-BNSs were investigated in detail. The prepared ox-BNSs were several-layered nanosheets with abundant oxygen-containing groups, emitted blue fluorescence, and possessed good intrinsic peroxidase mimetic activity, based on which a sensitive and selective colorimetric sensor was developed for detection of H2O2 and glucose. The new easy preparation strategy and good sensing performances of the prepared ox-BNSs would greatly stimulate the study and application of BNSs in chemo- and biosensing.

Functional Group Modulation in Carbon Quantum Dots for Accelerating Photocatalytic CO2 Reduction.

This study investigates the mechanism behind the enhanced photocatalytic performance of carbon quantum dot (CQD)-induced photocatalysts. Red luminescent CQDs (R-CQDs) were synthesized using a microwave ultrafast synthesis strategy, exhibiting similar optical and structural properties but varying in surface functional group sites. Model photocatalysts were synthesized by combining R-CQDs with graphitic carbon nitride (CN) using a facile coupling technique, and the effects of different functionalized R-CQDs on CO2 reduction were investigated. This coupling technique narrowed the band gap of R1-CQDs/CN, made the conduction band potentials more negative, and made photogenerated electrons and holes less likely to recombine. These improvements greatly enhanced the deoxygenation ability of the photoinduced carriers, increased light absorption of solar energy, and raised the carrier concentration, resulting in excellent stability and remarkable CO production. R1-CQDs/CN demonstrated the highest photocatalytic activity, with CO production up to 77 μmol g-1 within 4 h, which is approximately 5.26 times higher than that of pure CN. Our results suggest that the superior photocatalytic performance of R1-CQDs/CN arises from its strong internal electric field and high Lewis acidity and alkalinity, attributed to the abundant pyrrolic-N and oxygen-containing surface groups, respectively. These findings offer a promising strategy for producing efficient and sustainable CQD-based photocatalysts to address global energy and environmental problems.