Ni/WS2/WC Composite Nanosheets as an Efficient Catalyst for Photoelectrochemical Hydrogen Peroxide Sensing and Hydrogen Evolution.

It is highly attractive to develop a photoelectrochemical (PEC) sensing platform based on a non-noble-metal nano array architecture. In this paper, a PEC hydrogen peroxide (H2O2) biosensor based on Ni/WS2/WC heterostructures was synthesized by a facile hydrothermal synthesis method and melamine carbonization process. The morphology, structural and composition and light absorption properties of the Ni/WS2/WC catalyst were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-visible spectrophotometer. The average size of the Ni/WS2/WC nanosheets was about 200 nm. Additionally, the electrochemical properties toward H2O2 were studied using an electrochemical workstation. Benefiting from the Ni and C atoms, the optimized Ni/WS2/WC catalyst showed superior H2O2 sensing performance and a large photocurrent response. It was found that the detection sensitivity of the Ni/WS2/WC catalyst was 25.7 µA/cm2/mM, and the detection limit was 0.3 mmol/L in the linear range of 1-10 mM. Simultaneously, the synthesized Ni/WS2/WC electrode displayed excellent electrocatalytic properties in hydrogen evolution reaction (HER), with a relatively small overpotential of 126 mV at 10 mA/cm2 in 0.5 M H2SO4. This novel Ni/WS2/WC electrode may provide new insights into preparing other efficient hybrid photoelectrodes for PEC applications.

Association between enjoyment, physical activity, and physical literacy among college students: a mediation analysis.

Background: Physical literacy and enjoyment are important factors that affect physical activity. Purpose: This work studies whether physical activity enjoyment (PAE) mediates the association between moderate to vigorous physical activity (MVPA) and physical literacy (PL) among college students. Methods: Chinese college students were recruited using the Perceived Physical Literacy Instrument Scale (PPLI-SC), the International Physical Activity Questionnaire Short Form (IPAQ-SF), and the Physical Activity Enjoyment Scale. The SPSS Hayes process macro (model 4) was used to analyze the direct impact and the indirect impact. Pearson correlation, independent sample t-tests, and linear regression were used to analyze the relationship between indicators. Results: The study surveyed 587 boys and 1,393 girls with a total of 1,980 valid questionnaires. MVPA, PAE, and PL of boys were significantly higher than girls (p < 0.01). The correlation analysis showed that MVPA, PL, and PAE were significantly correlated (p < 0.01). The results showed the direct effect of PL on MVPA was still statistically significant (ß = 0.067, p < 0.05) after adding PAE variables; PAE has a positive effect on MVPA after controlling PL (ß = 0.170, p < 0. 01). PL has a positive effect on PAE (ß = 0.750, p < 0.01). PL impacted MVPA as explained by a 65.58% mediating effect of enjoyment. Conclusion: Physical activity enjoyment mediates the relationship between PL and MVPA among college students. This means that even high PL among student may not imply that they are physically active if they do not enjoy physical activity.

Research on the Relationship between Physical Literacy, Physical Activity and Sedentary Behavior.

During the COVID-19 pandemic, college students' health-related physical activity and physical literacy aroused widespread concern. This study evaluated the relationship among physical literacy (PL), sedentary behavior (SB), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA); we further explored whether LAP and SB mediated the association between PL and MVPA. METHODS: This study was based on a cross-sectional survey of Chinese college students. The Perceived Physical Literacy Instrument Scale (PPLI-SC) and International Physical Activity Questionnaire Short Form (IPAQ-SF) were used to investigate the PL, MVPA, LPA, and SB. RESULTS: There were 2996 valid questionnaires with 829 boys and 2167 girls. The MVPA, LPA, and PL of boys were significantly higher than girls, while the SB values were significantly lower in girls (p < 0.01). The correlation analysis showed that there was a significant correlation between the two indexes except for SB and LPA. Path analysis shows that PL directly, significantly, and positively affects MVPA. PL reduces SB (ß = -0.085, p < 0.001) and increases LPA (ß = 0.097, p < 0.001). The total mediation effect accounted for 14.014%, and the mediation effects of SB and LPA accounted for 4.417% and 9.597%, respectively. CONCLUSIONS: LPA and SB partially mediated the relation between PL and MVPA. SB and LPA partially explain the impact of PL on MVPA. The findings suggest that managing SB and improving LPA could play a significant indirect role in increasing the positive effect of PL on MVPA and that increasing the opportunities for LPA increased the MVPA for Chinese college students.