Unraveling the six stages of the current-time curve and the bilayer nanotubes obtained by one-step anodization of Zr.

The application and growth mechanism of anodic TiO nanotubes have been a hot topic in the last ten years, but the formation mechanism of anodic ZrO nanotubes has rarely been studied. In one-step constant voltage anodization of Al and Ti, the typical current-time curve has three stages. Moreover, the current-time curves of the three stages can last for 10 min or even 10 hours, resulting in a single layer of nanotubes with the same diameter due to the constant voltage in one-step anodization.

A review: research progress on the formation mechanism of porous anodic oxides.

Owing to the great development potential of porous anodic oxides (PAO) in many fields, research on their formation mechanisms, fabrication processes and applications has a history of more than ten years. Although compared with research on the fabrication processes and applications of PAO, research on their formation mechanisms started late, several mainstream theories have been formed in the academic community, including the field-assisted dissolution (FAD) theory, the field-assisted ejection (FAE) theory, the self-organization theory, the ionic and electronic current theory and the oxygen bubble mould effect. This review will focus on summarizing the core views of the mainstream mechanisms mentioned above and comparing the explanations for some of their classical experimental phenomena.

Organic Contaminants in Chinese Sewage Sludge: A Meta-Analysis of the Literature of the Past 30 Years.

The production of sewage sludge is increasing in China but with unsafe disposal practices, causing potential risk to human health and the environment. Using literature from the past 30 years (N = 159), we conducted a meta-analysis of organic contaminants (OCs) in Chinese sludge. Most data were available from developed and populated regions, and no data were found for Tibet.