This study explores the electrochemical modification of reduced graphene oxide (rGO) by incorporating 1,10-phenanthroline groups prior to the electrodeposition of silver nanoparticles (Ag NPs), aiming to enhance the performance on the oxygen reduction reaction (ORR). The introduction of 1,10-phenanthroline onto the rGO surface significantly improved its ability to coordinate metallic cations, compared to unmodified rGO. This enhanced coordination capacity led to a more efficient deposition of Ag NPs. Notably, increasing the amount of 1,10-phenanthroline groups grafted onto the rGO further boosted the number of deposited Ag NPs, substantially improving ORR performance. These results demonstrate that increasing the number of coordination units on rGO sheets prior to metal incorporation can significantly enhance the electrocatalytic efficiency of the resulting nanocomposites. This work emphasizes the importance of functionalizing rGO surfaces to optimize their catalytic properties for energy conversion and storage applications. This modification of rGO also paves the way for broader potential applications across various fields.

Graphene materials show great potential in the field of supercapacitors, but their tendency to agglomerate leads to a significant decrease in performance. Herein, manganese dioxide intercalated graphene oxide precursor was prepared using the modified Hummer method. During pyrolysis, manganese dioxide can not only act as a separator to prevent graphene aggregation but also undergo redox reactions with graphene to obtain oxygen-rich mesopore graphene (OMG). Benefiting from the mesoporous structure and abundant oxygen-containing functional groups, the OMG-600 electrode shows a specific capacitance of 248.67 F g− 1 at 0.5 A g− 1 and good electrochemical stability (92.25% capacitance retention after 10,000 cycles). Moreover, the assembled OMG-600//OMG-600 symmetric supercapacitor delivers an energy density of 17.69 Wh kg− 1 and superior electrochemical stabilization in 1 M Na2SO4 electrolyte.

Background: The preservation of boar semen is essential for optimizing artificial insemination outcomes and maintaining sperm functionality during liquid storage. Glucuronic acid (GA) is involved in cellular detoxification and homeostasis regulation and may relate to oxidative processes. However, its effect on boar semen preservation remains unclear. This study aimed to investigate the effects of GA addition on sperm viability, acrosome reaction, and intracellular ROS level during liquid storage in pigs. Methods: Boar semen was collected by the gloved-hand method and transported at 17℃. Samples were diluted with extenders containing 0, 0.5, 1.0, 2.5, and 5.0 mM GA and stored at 17℃ for 7 days. Sperm viability, acrosome reaction, and intracellular ROS levels were detected using SYBR-14/PI, FITC-PNA/PI, and DCFDA/PI double staining and analyzed by flow cytometry. Results: Sperm viability was higher in the 0.5 mM GA group than in the 0 mM group at 72 h, with no difference at 120 h and 168 h. Acrosome reaction showed no difference at 72 h and 120 h, but was lower in the 5.0 mM group than in the 0 mM group at 168 h. Intracellular ROS levels were similar among treatments at 72 h and 168 h, but were higher in the 5.0 mM group than in the 0 mM group at 120 h. Conclusions: GA supplementation showed concentration- and storage-dependent effects, with a transient viability increase at 0.5 mM (72 h) and a reduced proportion of acrosome-reacted sperm at 5.0 mM (168 h), while ROS was not decreased and was elevated at 5.0 mM at 120 h, suggesting the need for dose optimization.

본 연구에서는 산업계의 높은 에너지 소비를 줄이기 위한 에너지 효율적 분리 공정의 일환인 분리막 기술을 이용 하여, 우수한 산소 차단막을 개발을 목표로 하였다. 기존 화학적 처리 방식과 달리, 고유의 결정 구조가 보존되어 있는 물리 적 분쇄된 실크 피브로인 분말을 polyvinyl alcohol (PVA) 고분자 용액과 혼합하여 복합막을 성공적으로 제조하였다. 이때 물 리적 분쇄 과정에서 발생한 미세 입자가 유발하는 공정상의 기포 문제는 분말 세척을 통해 효과적으로 억제하였다. Time-lag 측정 결과, 제조된 복합막은 실크 입자가 기체 확산 경로를 방해하는 tortuous path를 형성하여 확산도와 용해도를 급격히 감 소시켰다. 그 결과, 순수 PVA 막 대비 압도적으로 우수한 산소 차단 성능을 나타내며 친환경 고성능 차단 소재로서의 가능성 을 확인하였다.

Efficient energy conversion technologies require cost-effective and durable catalysts for water oxidation. This study presents SnS2/ C composite synthesized via solvothermal method to enhance electrocatalytic performance in water splitting. Morphological analysis reveals that carbon incorporation disrupts the flower-like SnS2 nanosheets, increasing active site accessibility and improving charge transfer efficiency. Three different electrolytes (KOH, PBS and H2SO4) are systematically employed to evaluate the material’s electrocatalytic activity comprehensively. The electrochemical tests indicate that pure SnS₂ exhibits an overpotential (η) of 410 mV at 10 mA/cm2 for oxygen evolution reaction (OER) in 1 M KOH. Integration of carbon significantly lowers this value to 180 mV with a tafel slope of 103 mV/dec for SSC12 (1:2 SnS₂/C) composite. For hydrogen evolution reaction (HER) in acidic media, SSC12 achieves an η of 275 mV at 500 mA/cm2 with a tafel slope of 121 mV/dec. The catalyst further demonstrates strong durability for OER in 1 M KOH but shows diminished HER activity in 0.5 M H2SO4. This study demonstrates the synergistic role of carbon in enhancing SnS₂ catalytic attributes, emphasizing the potential of these composites for sustainable energy conversion applications.

하수처리장 전력 사용량의 50∼65%를 사용하는 송풍기 사용 동력 절감은 Scope 2 탄소발생을 감소시킨다. 일반적으로 국내 하수처리장은 설계기준인 일 최대 유입하수량과 유입 수질 유입 시 방류수 배출기준을 만족하도록 설계된 운전 방법으로 상시 가동하는데, 일반적인 특성을 가진 하수를 처리하는 경우 이에 맞춘 운전을 하면 송풍 동력을 절감할 수 있다. 본 연구에서는, 시뮬레이션을 통해 일반적인 하수를 처리하는 경우 4개로 구분된 호기조 중 3개만 폭기하고, 말단 호기조의 용존산소 농도와 암모니아성 질소 농도를 기준으로 전체 호기조 공급 송풍량을 조절하면 폭기 에너지를 절약할 수 있는 것으로 파악되었다. 말단 호기조 용존산소 농도를 1.5 ㎎/L로 상시 유지하고, 시간 최대 암모니아성 질소 농도를 상시 4.0 ㎎/L 이하로 유지시키는 다단 제어시스템을 도입하면 전체적으로 설계운전에 비해 16.2%의 송풍량이 절감이 될 수 있는 것으로 시뮬레이션을 통해 파악되었다. 또한 16.2% 의 송풍량 절감은 0.00599 kg CO2.eq./m3, 연간 102.7 ton의 Scope 2 탄소 발생을 절감하는 것으로 나타나, 다단제어를 포함한 Digital Twin을 실 처리장에 적용하면 송풍량 최적화를 통한 탄소발생 저감이 수행될 수 있는 것으로 나타났다.

The postharvest quality of cut flowers often declines during transportation, especially under dry storage conditions. Therefore, incorporating preservative solutions during shipment is vital for extending the vase life of high-value cut flowers. Among commonly used additives, sucrose (Suc) and Floralife (FL), a commercial preservative, have demonstrated efficacy in maintaining vase life. Oxygen nanobubbles (O2NB) and ozone nanobubbles (O3NB), which are nanoscale gas-filled bubbles in aqueous media, have been proposed as antimicrobial agents for use in preservative solutions applied to cut flowers. This study examined the effects of seven preservative treatments on the postharvest performance of cut Cymbidium ‘Lovely King’ during simulated transport. Treatments included tap water (control), Suc, FL, O2NB, O2NB combined with Suc (O2NBS), O3NB, and O3NB combined with Suc (O3NBS). Cut stems were placed in floral water tubes filled with the respective solutions and stored in a cold chamber at 5°C for 7 days to simulate transport conditions. Among the treatments, O2NB resulted in the longest vase life of 21.0 days, significantly longer than that under O2NBS (14.3 days). Additionally, the O2NB solution exhibited the lowest bacterial count (4.9 log 10 CFU mL-1) compared with other treatment solutions. Stems treated with O3NB maintained the highest relative fresh weight throughout the experiment. Initial water uptake was 8.4 g and 7.6 g for the O3NB and O2NB treatments, respectively. These findings indicate that O2NB is an effective transport preservative for enhancing postharvest quality and extending the vase life of cut Cymbidium ‘Lovely King.’

We present an atomistic investigation of the oxygen activation of a Pt nanoparticle with 147 atoms (Pt147), focusing on the role of microfacets. Using density functional theory (DFT) calculations, we evaluated the adsorption energy (Ead) of both molecular and atomic oxygen across the surface, along with the activation energy barrier (Eact) for O2 dissociation and subsequent atomic oxygen diffusion. The Pt147 exhibited a facet-dependent variation in O2 adsorption, while atomic oxygen displayed a relatively uniform Ead across the surface. This suggests that atomic oxygen can readily participate in surface reactions regardless of the location. The diffusion Eact values of atomic oxygen calculated along various pathways were lower than 0.61 eV, confirming the high surface mobility of oxygen atoms. Interestingly, we found a clear linear correlation between the Ead of O2 on Pt147 and the Eact of subsequent O2 dissociation. The results show that Pt nanoparticles with well-developed microfacets can efficiently activate molecular oxygen and facilitate oxidation reactions.

Photocatalysis technology including hydrogen evolution from water splitting, CO2 reduction and N2 conversion to ammonia emerges as a significant approach for energy crisis and environmental pollution. For these conventional semiconductors such as TiO2, ZnO, WO3, CdS and g-C3N4, however, inefficient photoabsorption, rapid recombination of photogenerated carriers, and inadequate surface reactive sites hamper the photoinduced activity and stability. Defect engineering, especially oxygen vacancy, has recently drawn the attention of a number of investigators primarily in connection with its feasibility of regulatability, identifiability and effectiveness. A series of ferroelectric and piezoelectric semiconductors, with internal electric field generated by the polarization, are considered an excellent candidate for replacement of conventional semiconductors, because the observed charge separation ability of those is far from theoretical expectation. With the boost of oxygen vacancy, polarization behavior can be effectively regulated to further improve photocatalytic performance. Related studies based on the above background are the current hotspot of photocatalysis; this paper reviews the latest research progress of ferroelectric and piezoelectric photocatalysts with oxygen vacancy. Starting from the generation of oxygen vacancies, five preparation strategy including ion doping, thermal treatment, chemical reduction, ultraviolet irradiation, and plasma etching are introduced; advanced characterization are summarized in classification of spectroscopy, energy spectrum, electron microscopy, density function theory and in situ techniques. Secondly, the mechanism of oxygen vacancy regulated polarization and their synergistic photocatalytic reactions are reviewed and summarized. Finally, an overview on the prospect of advanced photocatalytic engineering concerned to oxygen vacancies involved ferroelectric and piezoelectric photocatalysts is proposed.

Low-loaded (1–5 wt%) platinum on carbon-based electrocatalysts (l-Pt/C) for the oxygen reduction reaction (ORR) has garnered attention as a promising approach to advancing fuel cell commercialization. Carbon materials, known for their morphological diversity, high specific surface area, ease of doping, cost-effectiveness, and high electrical conductivity, are widely used as supports for l-Pt/C catalysts. This review provides a comprehensive overview of recent progress in carbonbased l-Pt/C catalysts, focusing on three major strategies: modulating pore structure, utilizing the Pt size effect, and introducing novel Pt active sites. Each strategy is detailed, highlighting its principles, characteristics, and limitations with illustrative examples. Finally, we discuss and offer guidance for future research perspectives on highly active l-Pt/C catalysts for ORR.

With increasing globalization and the urgent need for sustainable energy solutions, electrochemical water splitting has emerged as a crucial technology for clean energy production. In this study, we report the successful synthesis of 0.1 % Fe-doped NiS2 via a one-step hydrothermal method. The incorporation of Fe into the NiS2 matrix significantly enhances its electrochemical performance, as evidenced by a remarkable reduction in overpotential, to 180 mV at a current density of 10 mA cm-2, compared to 250 mV for undoped NiS2. Additionally, the Fe-doped NiS2 exhibits a reduced Tafel slope, high double layer capacitance, and lower charge transfer resistance than undoped NiS2, indicating improved reaction kinetics for oxygen evolution. These improvements are attributed to the enhanced conductivity and catalytic activity imparted by Fe doping, which facilitates more efficient charge transfer and reaction processes at the electrode surface. The results suggest that Fe-doped NiS2 is a highly promising and robust candidate for applications in electrochemical energy conversion. Moreover, the doping strategy employed here offers a valuable approach for tailoring the properties of other metal sulfides and chalcogenides, paving the way for the design of next generation electrocatalysts that can drive large-scale energy conversion processes with minimal energy loss.

이 연구의 목적은 이완을 유도하는 향과 고농도 산소를 결합한 자극이 심리적/생리적 반응에 미치는 영향을 탐구 하는 것이다. 같은 향 조건 하에서 산소 농도를 조절했을 때 나타나는 뇌혈류 반응과 각성도가 관찰되었다. 실험에 사용된 향은 라벤더 오일(이완 향)이었고, 산소 농도로는 일반 농도 산소(21%)와 고농도 산소(30%)가 사용되었다. 실험은 총 12명의 성인 남성을 대상으로 휴식 기간(5분)과 자극 기간(5분)을 반복하여 실시되었다. 뇌혈류 반응을 관찰하기 위해 비어-램버트(Beer-Lambert) 법칙에 따라 헤모글로빈(HbO) 농도가 추출되었다. 각성도는 5점 척도 설 문지를 사용하여 평가되었다. 두 자극(라벤더+21%, 라벤더+30%) 간 비교를 위해 쌍체 t-검정이 실시되었다. 결과적 으로 라벤더+30%에서 라벤더+21%에 비해 전두엽의 HbO 농도가 증가하고 각성도가 감소하였다. 이 결과들은 기존 의 향 자극에 고농도 산소가 추가된 복합 자극이 더 많은 뇌 활성화와 이완을 유도할 수 있음을 시사한다.

Electrochemical water splitting presents an optimal approach for generating hydrogen ( H2), a highly promising alternative energy source. Nevertheless, the slow kinetics of the electrochemical oxygen evolution reaction (OER) and the exorbitant cost, limited availability, and susceptibility to oxidation of noble metal-based electrocatalysts have compelled scientists to investigate cost-effective and efficient electrocatalysts. Bimetallic nanostructured materials have been demonstrated to exhibit improved catalytic performances for the oxygen evolution reaction (OER). Herein, we report carbon aerogel (CA) decorated with different molar ratios of Fe and Ni with enhanced OER activity. Microwave irradiation was involved as a novel strategy during the synthesis process. Inductively coupled plasma mass spectrometry (ICP-MS), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscope (SEM), Energy dispersive X-ray spectroscopy (EDAX spectra and EDAX mapping), Transmission Electron Microscope (TEM), High-Resolution Transmission Electron Microscope (HR-TEM), and Selected Area Electron Diffraction (SAED) were used for physical characterizations of as-prepared material. Electrochemical potential towards OER was examined through cyclic voltammetry (CV), chronoamperometry, and electrochemical impedance spectroscopy (EIS). The FeNi/CA with optimized molar ratios exhibits low overpotential 377 mV at 10 mAcm− 2, smaller Tafel slope (94.5 mV dec− 1), and high turnover frequency (1.09 s− 1 at 300 mV). Other electrocatalytic parameters were also calculated and compared with previously reported OER catalysts. Additionally, chronoamperometric studies confirmed excellent electrochemical stability, as the OER activity shows minimal change even after a stability test lasting 3600 s. Moreover, the bimetallic (Fe and Ni) carbon aerogel exhibits faster catalytic kinetics and higher conductivity than the monometallic (Fe), which was observed through EIS investigation. This research opens up possibilities for utilizing bi- or multi-metallic anchored carbon aerogel with high conductivities and exceptional electrocatalytic performances in electrochemical energy conversion.

Photocatalytically splitting water into hydrogen upon semiconductors has tremendous potential for alleviating environmental and energy crisis issues. There is increasing attention on improving solar light utilization and engineering photogenerated charge transfer of TiO2 photocatalyst because it has advantages of low cost, non-toxicity, and high chemical stability. Herein, oxygen vacancies and cocatalysts (Cu and MoS2) were simultaneously introduced into TiO2 nanoparticles from protonic titanate by a one-pot solvothermal method. The composition and structure characterization confirmed that the pristine TiO2 nanoparticle was rich in oxygen vacancies. The photocatalytic performances of the composites were evaluated by solar-tohydrogen evolution test. The results revealed that both Cu-TiO2 and MoS2- TiO2 could improve the photocatalytic hydrogen evolution ability. Among them, 0.8% Cu-TiO2 showed the best hydrogen evolution rate of 7245.01 μmol·g−1·h−1, which was 3.57 and 1.34 times of 1.25% MoS2- TiO2 (2726.22 μmol·g−1·h−1) and pristine TiO2 material (2028.46 μmol·g−1·h−1), respectively. These two kinds of composites also had good stability for hydrogen evolution. Combined with the results of photocurrent density and electrochemical impedance spectra, the incorporation of oxygen vacancies and cocatalysts (Cu and MoS2) could not only enhance the light-harvesting of TiO2 but also improve the separation and transfer capabilities of light-induced charge carriers, thus promoting water splitting to hydrogen.