Synthesis and electrochemical evaluation of nickel hydroxide nanosheets with phase transition to nickel oxide.

Transition metal hydroxides are commonly used to develop nanostructures with desired functionalities by controlling their size, morphology, and structure. In this study, nickel hydroxide nanosheets with a hexagonal island shape are synthesized via a surfactant-assisted method. Using this method, nickel hydroxide nanosheets can be easily achieved in a quick manner. The synthesized nanosheets are 3-6 nm thick and exhibit a curly and wrinkled morphology with increasing surfactant concentration. These nanosheets demonstrate superior catalytic properties for the oxygen evolution reaction activity compared to nickel oxide sheets obtained via a simple heat treatment. Furthermore, we conduct surface enhanced Raman scattering analysis to confirm that the nickel hydroxide nanosheets serve as active species for NiOOH during the oxygen evolution reaction, and we propose an electrochemical mechanism for this system. This study not only presents the detailed synthesis process but also proposes a straightforward approach, offering valuable insights into the structural and electrochemical properties of the resulting nanosheets.

Facile route of fluorine incorporation into nickel (oxy)hydroxide for improving the oxygen evolution reaction.

Despite extensive development, oxygen evolution reaction (OER) catalysts still require significant overpotentials to function. In this study, we show that the overpotential of a nickel (Ni) electrode for the OER can decrease by about 100 mV with fluorine (F) incorporation, particularly by a facile electrochemical approach at room temperature.

Factors Affecting the Public Intention to Repeat the COVID-19 Vaccination: Implications for Vaccine Communication.

Although most of the pandemic-related mandatory restrictions have been lifted or eased, vaccination is still recommended as an effective measure to minimize the damage from COVID-19 infection. Since COVID-19 eradication is unlikely, it is necessary to understand the factors affecting the public's vaccination intention when COVID-19 vaccination is continuously recommended. This study aims to explore the factors that affect the intention to repeat the COVID-19 vaccination in South Korea. An online survey was conducted in January 2022 with adults living in Gyeonggi-do, South Korea. In a hierarchical logistic regression analysis, sociodemographic factors, COVID-19 infection-related factors, COVID-19 vaccination-related factors, sociocultural factors, and communication factors were taken into account. In this study, more than three-quarters (78.1%) of Koreans were willing to repeat the COVID-19 vaccination. People who had high-risk perceptions, had been vaccinated against COVID-19 at least once, had more authoritarian attitudes, regarded the vaccination as a social responsibility, and had positive attitudes toward health authorities' regular briefings were more likely to repeat the vaccination. In contrast, those who directly or indirectly experienced COVID-19 vaccine side effects and who showed psychological reactance against the government's vaccination recommendation were less likely to repeat the vaccination. Our research indicates that empathetic communication, promotion of the prosocial aspect of vaccination, and regular and transparent provision of vaccine information are essential for promoting the intention to repeat the COVID-19 vaccination.