B,N-decorated carbocatalyst based on Fe-MOF/BN as an efficient peroxymonosulfate activator for bisphenol A degradation.

A novel B,N-decorated carbocatalyst (Fe@BPC-XBN) for peroxymonosulfate (PMS) activation was prepared by a simple pyrolysis method using the iron-based metal organic frameworks (Fe-MOF), boric acid and boron nitride (BN) as precursors. Fe@BPC-20BN removed 93.3% of bisphenol A (BPA) in 90 min compared to 64.9%, 82.1% and 83.5% with Fe@PC, Fe@BPC and Fe@PC-20BN, respectively, with 0.15 g/L catalyst and 1 mM PMS at initial pH of 7. The solo B-doping with boron acid on the Fe-MOF derived porous carbon enhanced its catalytic capacity; moreover, B, N co-doping with BN and boron acid as precursors further promoted the catalytic performance. The addition of BN not only provided more B, N catalytic centers but also improved the stability of the carbocatalyst. In addition, hydroxyl radicals, sulfate radicals, superoxide radicals, and singlet oxygen species were involved in the degradation of BPA. Fe species, -BCO2/-BC2O, pyridinic N, and pyrrolic N groups on the carbon matrix played the important roles in the BPA degradation. The outstanding catalytic performance of Fe@BPC-20BN could be attributed to the synergistic effects between iron nanoparticles and the B/N codoped carbon matrix. This study gives new insights into the design and preparation of high-efficient B,N-decorated carbocatalysts for environmental remediation.

A review of atmospheric microplastics pollution: In-depth sighting of sources, analytical methods, physiognomies, transport and risks.

Micro-sized plastics were first examined for atmospheric environment in 2016. From then on, they have been detected in both indoor and outdoor atmospheric samples, with indoor environments demonstrated as containing a big proportion of these particles. The sparse distribution of these particles, is attributed to their swift and long distance transportation that is mainly eased by their tiny size (1 µm to 5 mm) and low density. Due to ongoing limitation on detectable size, analysis methods together with a lack of standardized sampling and analytical procedures, few studies were conducted on airborne microplastics (MPs). Thus, the facts regarding the occurrence, global spatial distribution, fate, and threats to ecosystem and human health of airborne MPs, are still far from being fully clarified. This literature review is a broad depiction of a state of knowledge on atmospheric MPs. Within it, robust and concise information on the sources, inspection, transport, and threats pertaining to airborne MPs are presented. Particularly, the paper entails some information concerning traffic-generated MPs pollution, which has not been frequently discussed within previously published reports. In addition, this paper has widely unveiled sectors and aspects in need of further attention, with the gaps to be filled pinpointed.

Facile synthesis of flower-like hierarchical N-doped Nb2O5/C nanostructures with efficient photocatalytic activity under visible light.

Significant endeavors have been devoted in the past few years to establish efficient visible light-activated photocatalysts. Herein, we successfully synthesized a flower-like hierarchical nitrogen-doped and carbon-sensitized Nb2O5 (NBO) nanostructure (denoted N-NBO/C). The as-prepared N-NBO/C possessed a specific surface area of 260.37 m2 g-1 and single wire diameter of less than 10 nm. The effect of reaction parameters such as hydrothermal reaction time, temperature and concentration of hexamethylenetetramine (Hmta) on the morphology of NBO was systematically investigated to elucidate the growth mechanism. The carbon on the surface and the nitrogen in the framework of NBO are beneficial for light harvesting, visible light absorption, formation of oxygen vacancies, and electron-hole separation. The photocatalytic performance of the as-fabricated N-NBO/C nanostructures was estimated via the photodegradation of 30 mg L-1 RhB, where greater than 98% of RhB was decomposed within 30 min upon visible-light radiation. Hence, the obtained N-NBO/C nanostructure exhibits much higher photocatalytic activity for the decomposition of RhB upon visible light irradiation than that of pure niobium oxide (NBO), nitrogen-doped titanium oxide (N-TIO), and nitrogen-doped niobium oxide (N-NBO). This work supplies a versatile route for the synthesis of nitrogen-doped and carbon-sensitized metal-oxide nanostructures for possible utilization in solar energy transformation and environmental remediation.