In this paper, we developed a new safe and facile route to prepare black titania at room temperature for visible light photocatalysis. The commercial Degussa P25 was used as the starting material, and it was hydrogenated at 35 bar hydrogen and room temperature for up to 20 days. The resulting hydrogenated P25 was characterized by XRD, FT-IR, Raman, UV-Vis, TEM and photocatalysis tests under visible light in methanol solution. It was found that P25 powders under hydrogen treated for more than 15 days have a dark appearance, a crystalline-disordered core-shell structure, unique phase structure and good photocatalytic performance. The H 2 evolution rates are 3.14, 3.56 and 3.94 mmol g À1 h À1 in 20% methanol solution for hydrogen treated P25 at 15, 17 and 20 days, respectively, which were largely higher than that with hydrogen treatment time less than 11 days. This work will provide a practical, green and facile method for the large scale synthesis of black titania at room temperature.

The COVID-19 pandemic causes severe morbidity and mortality. This multi-country study aimed to explore risk factors that drive mortality in COVID-19 patients who received neither dexamethasone nor remdesivir. We analyzed a cohort of 568 survivors and 507 non-survivors from China, European regions, and North America. Elderly males ≥70 years accounted for only 25% of survivors, but this rate was significantly higher in non-survivors from China (55%), European regions (63%), and North America (47%). Compared with survivors, non-survivors had more incidences of comorbidities such as cerebrovascular disease and chronic obstructive pulmonary disease (COPD, p-values<0.05). Survival analyses revealed age, male gender, shortness of breath, cerebrovascular disease, and COPD as mortality-associated factors. Survival time from symptom onset was significantly shorter in elderly versus young patients (median: 29 versus 62 days), males versus females (median: 46 versus 59 days), and patients with versus without comorbidities (mean: 41 versus 61 days). Mortality risk was higher in elderly males with comorbidities than in young females without comorbidities (p-value<0.01). Elderly male survivors with comorbidities also had longer hospital stays than other survivors (25 versus 18.5 days, p-value<0.01). Overall, the high mortality risk in elderly males with COVID-19-associated comorbidities supports early prevention and critical care for elderly populations.

Zeolitic imidazole framework-67 derived hollow nanomaterials were prepared by etching technique and used as solid-phase microextraction coating, which provided a new, effective and low-cost method for the rapid capture of PAHs from real samples.

Zn-modified ZSM-5 catalysts were widely used in ethylene aromatization; however, the deactivation and regeneration behavior of these catalysts have not been fully understood. In this work, the structure evolution of Zn species on various x-Zn(y)/Z5 catalysts prepared by ion exchange, incipient wetness impregnation, and physical mixture in ethylene aromatization were systemically investigated. The results of X-ray diffraction, X-ray photoelectron spectroscopy, DR UV–vis, 27Al/29Si MAS NMR, EXAFS, and X-ray absorption near edge spectra with LCF analysis indicated that the generated coke species on spent Zn/ZSM-5 can not only cover the acid sites and block the pore channel but also lead to the transformation of active 6-fold coordinated ZnOH+ species into unactive 4-fold coordinated ZnO. After regeneration to eliminate these carbon deposits, the crystallinity, specific surface area, pore volume, and total acid content of regenerated Zn/ZSM-5 were fully recovered. More importantly, most of the ZnO clusters/crystals were converted into ZnOH+ species again. As a result, the regenerated Zn/ZSM-5 catalysts showed even higher aromatic selectivity than the fresh one in ethylene aromatization.