Recent Advances of Graphitic Carbon Nitride-Based Structures and Applications in Catalyst, Sensing, Imaging, and LEDs

The graphitic carbon nitride(g-C_3N_4) which is a two-dimensional conjugated polymer has drawn broad interdisciplinary attention as a low-cost, metal-free, and visible-light-responsive photocatalyst in the area of environmental remediation. The g-C_3N_4-based materials have excellent electronic band structures, electron-rich properties, basic surface functionalities, high physicochemical stabilities and are ‘‘earth-abundant.'' This review summarizes the latest progress related to the design and construction of g-C_3N_4-based materials and their applications including catalysis, sensing,imaging, and white-light-emitting diodes. An outlook on possible further developments in g-C_3N_4-based research for emerging properties and applications is also included.

Knowledge Mapping of Opuntia Milpa Alta Since 1998: A Scientometric Analysis

Opuntia Milpa Alta is a cactus cultivated,domesticated,hybridized and selected from the plant Opuntia ficusindica by Mexican agricultural experts,which can be used as fruit and vegetable.Opuntia Milpa Alta leaves and fruit are superior to wild varieties and suitable for storage and transportation.In 1998,Opuntia Milpa Alta was introduced to China from Mexico by the Quality Product Development Center of the Ministry of Agriculture of China.Up to now,the Opuntia Milpa Alta has been cultivated on a certain scale in China.This study aims to identify the research progress and development trends of Opuntia Milpa Alta in China.Papers published between 1998 to 2019 from two major Chinese academic databases(CNKI and Wangfang)with a topic search related to Opuntia Milpa Alta were collected.The research progress and development trends were analyzed based on CiteSpace software of text mining and visualization.The analysis found that Opuntia Milpa Alta has gone through three obvious research phases after being introduced to China.In the first phase,the researchers paid attention to its cultivation method.Subsequently,researchers began to use extraction methods to extract some of its components,such as polysaccharides and flavonoids.Finally,these extracted ingredients began to be used in some biomedical research.

A highly stable, luminescent and layered zinc(Ⅱ)-MOF:Iron(Ⅲ)/copper(Ⅱ) dual sensing and guest-assisted exfoliation

A highly stable and luminescent metal-organic framework(LMOF) with layered structure,namely,C6H4N5OZn(1) has been successfully achieved and fully characterized by single crystal X-ray diffraction,powder X-ray diffractions,fluorescence titration and thermogravimetry.This blue-light emitting compound 1 exhibit outstanding stability and can detect Fe3+ and Cu2+ in water specifically,presenting potential application in the field of fluorescent probe technology.Fluorescence titration experiments indicate that the detection of Fe3+ ions by 1 is more significant than that of Cu2+ ions in terms of Ksv value.Furthermore,guest-assisted exfoliation of layered MOF 1 is efficiently carried out through ether O—H hydrogen bond or π…π interactions between the layered host structure and intercalated guest molecules(4,4’-oxybisbenzoic acid and triphenylamine).Tyndal scattering was observed in the suspensions of obtained MOF nanosheets.This study shows that the compound 1 with unique metal ion sensing properties can be applied as a probe material in water pollution treatment field,but also opens up the opportunity for synthesizing luminescent MONs through the "bottom-up" guest intercalation methodology.