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  • Publication
    Embargo
    Tailored heterostructured Ni3N-NiO nano-frameworks for boosting electrocatalytic oxygen evolution via surface-modulated plasma strategy
    (Springer, 2024)
    Ouyang, Bo
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    Qin, Haonan
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    Sun, Chao
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    Deng, Yilin
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    Li, Ang
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    Zhu, Jipeng
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    Kan, Erjun
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    The facile reconfiguration of phases plays a pivotal role in enhancing the electrocatalytic production of H2 through heterostructure formation. While chemical methods have been explored extensively for this purpose, plasma-based techniques offer a promising avenue for achieving heterostructured nano-frameworks. However, the conventional plasma approach introduces complexities, leading to a multi-step fabrication process and challenges in precisely controlling partial surface structure modulation due to the intricate interaction environment. In our pursuit of heterostructures with optimized oxygen evolution reaction (OER) behavior, we have designed a facile auxiliary insulator-confined plasma system to directly attain a Ni3N-NiO heterostructure (hNiNO). By meticulously controlling the surface heating process during plasma processing, such approach allows for the streamlined fabrication of hNiNO nano-frameworks. The resulting nano-framework exhibits outstanding catalytic performance, as evidenced by its overpotential of 320 mV at current densities of 10 mA cm-2, in an alkaline environment. This stands in stark contrast to the performance of sNiNO fabricated using the conventional plasma method. Operando plasma diagnostics, coupled with numerical simulations, further substantiate the influence of surface heating due to auxiliary insulator-confinement of the substrate on typical plasma parameters and the formation of the Ni3N-NiO nanostructure, highlighting the pivotal role of controlled surface temperature in creating a high-performance heterostructured electrocatalyst.
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  • Publication
    Metadata only
    Promoting hEalthy Diet and Active Lifestyle (PEDAL): A protocol for the development and feasibility study of a multicomponent intervention among primary school children in Singapore
    (BMC, 2024)
    Chan, Cindy Mei Jun
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    Muller-Riemenschneider, Falk
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    Hildon, Zoe Jane-Lara
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    Chong, Mary Foong-Fong
    Background Setting healthy lifestyle habits during the formative years of childhood is critical as habits can track to adulthood and help prevent obesity and chronic disease risks in later life. While multicomponent interventions have been shown to be effective in changing the lifestyle behaviours of children, there is a limited understanding of the feasibility of such interventions in primary schools in Singapore. A multiphase mixed method study was conducted to develop and examine the feasibility of a theory-based multicomponent school-based intervention—Promoting hEatlthy Eating and Active Lifestyle (PEDAL). Methods Underpinned by Kincaid’s ideation model, the PEDAL intervention was developed to increase fruit and vegetable consumption and decrease sedentary behaviours among children. This study consists of three phases. Phase 1 details the development of PEDAL, which consists of four components: (A) a series of interactive health education lessons, (B) actionable home activities to support habit formation, (C) parental/guardian engagement, and (D) optimising the school environment. In Phase 2, components A and B of PEDAL were implemented in two public, co-educational primary schools among Primary 5 students (aged 10–12 years) in Singapore. Data was collected quantitatively using questionnaires and qualitatively using focus group discussions (FGDs) with students and teachers. The feasibility dimensions of components A and B, including recruitment capability, data collection, social validity, and practicality were examined, and ideation on healthy eating and physical activity was explored. In Phase 3, the full PEDAL intervention was pilot-tested in two other public, co-education primary schools with the same target population, using a concurrent mixed method quasi-experimental study design. Feasibility dimensions and potential effectiveness of the intervention will be assessed. Discussion This study will provide insights into the feasibility of PEDAL and inform its refinement. Findings from the pilot test will guide the planning of a larger-scale definitive trial.
      4
  • Publication
    Embargo
    Trends of physical activity and sedentary behaviours among secondary school students in Singapore: What has changed in 15 years?
    (Taylor & Francis, 2024) ; ; ; ;
    Chian, Zason Lit Khoon
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    Sumarta, Tin Tin
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    Swarup Mukherjee
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    Tan, Yi Jie
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    Gooley, Joshua
    The objective of the current study was to examine the trends of physical activity (PA) and sedentary behaviour (SB) of adolescents in Singapore with two datasets 15 years apart (2006 and 2021). A total sample of 1075 secondary students (mean age = 14.91 ± 0.43 years old) from 15 schools in Singapore took part in the study. A seven-day recall Self-administered Physical Activity Checklist (SAPAC) questionnaire was used to capture time spent on the internet/computer, gaming, homework, reading, sitting and talking/listening to music, telephone, television watching, and PA. Results showed that the 2021 sample spent significantly more time on gaming, homework, sit and talk/listening to music, phone, and PA compared to the 2006 sample, while time spent watching television was significantly lower than the 2006 sample. Both datasets found PA had low or close to zero correlations with all the seven SB, however, the patterns of correlations were different in the two datasets, indicating changes in the trends of SB and PA. Cluster analysis found similar cluster profiles in the two samples but the cluster proportions for certain profiles were different from the two datasets. Significant sex differences were also found in the cluster compositions. Overall, this study shows that PA and SB trends of adolescents have changed significantly.
      7  6
  • Publication
    Unknown
    Advancing lithium–magnesium separation: Pioneering swelling-embedded cation exchange membranes based on sulfonated poly(ether ether ketone)
    (American Chemical Society, 2024)
    Qian, Hao
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    Xu, Geting
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    Yang, Shanshan
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    Chen, Quan
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    Lin, Chenfei
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    Liao, Junbin
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    Shen, Jiangnan
    With the continuous advancement of electrodialysis (ED) technology, there arises a demand for improved monovalent cation exchange membranes (CEMs). However, limitations in membrane materials and structures have resulted in the low selectivity of monovalent CEMs, posing challenges in the separation of Li+ and Mg2+. In this investigation, a designed CEM with a swelling-embedded structure was created by integrating a polyelectrolyte containing N-oxide Zwitterion into a sulfonated poly(ether ether ketone) (SPEEK) membrane, leveraging the notable solubility characteristic of SPEEK. The membranes were prepared by using N-oxide zwitterionic polyethylenimine (ZPEI) and 1,3,5-benzenetrlcarbonyl trichloride (TMC). The as-prepared membranes underwent systematic characterization and testing, evaluating their structural, physicochemical, electrochemical, and selective ED properties. During ED, the modified membranes demonstrated notable permeability selectivity for Li+ ions in binary (Li+/Mg2+) systems. Notably, at a constant current density of 2.5 mA cm–2, the modified membrane PEI-TMC/SPEEK exhibited significant permeability selectivity (PLi+Mg2+=5.63) in the Li+/Mg2+ system, while ZPEI-TMC/SPEEK outperformed, displaying remarkable permeability selectivity (PLi+Mg2+=12.43) in the Li+/Mg2+ system, surpassing commercial monovalent cation-selective membrane commercial monovalent cation-selective membrane (CIMS). Furthermore, in the Li+/Mg2+ binary system, Li+ flux reached 9.78 × 10–9 mol cm–2 s–1 for ZPEI-TMC/SPEEK, while its Mg2+ flux only reached 2.7 × 10–9 mol cm–2 s–1, showing potential for lithium–magnesium separation. In addition, ZPEI-TMC/SPEEK was tested for performance and stability at high current densities. This work offers a straightforward preparation process and an innovative structural approach, presenting methodological insights for the advancement of lithium and magnesium separation techniques.
      3
  • Publication
    Metadata only
    Structural regulation of coal-derived hard carbon anode for sodium-ion batteries via pre-oxidation
    (Springer, 2024)
    Su, Meng-Yuan
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    Zhang, Kai-Yang
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    Zhang, Xue-Li
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    Liu, Yan-Ning
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    Yang, Jia-Lin
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    Gu, Zhen-Yi
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    Butt, Faaz A.
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    Wu, Xing-Long
    Hard carbon (HC) is broadly recognized as an exceptionally prospective candidate for the anodes of sodium-ion batteries (SIBs), but their practical implementation faces substantial limitations linked to precursor factors, such as reduced carbon yield and increased cost. Herein, a cost-effective approach is proposed to prepare a coal-derived HC anode with simple pre-oxidation followed by a post-carbonization process which effectively expands the d002 layer spacing, generates closed pores and increases defect sites. Through these modifications, the resulting HC anode attains a delicate equilibrium between plateau capacity and sloping capacity, showcasing a remarkable reversible capacity of 306.3 mAh·g−1 at 0.03 A·g−1. Furthermore, the produced HC exhibits fast reaction kinetics and exceptional rate performance, achieving a capacity of 289 mAh·g−1 at 0.1 A·g−1, equivalent to ~ 94.5% of that at 0.03 A·g−1. When implemented in a full cell configuration, the impressive electrochemical performance is evident, with a notable energy density of 410.6 Wh·kg−1 (based on cathode mass). In short, we provide a straightforward yet efficient method for regulating coal-derived HC, which is crucial for the widespread use of SIBs anodes.
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