Synergistic visible light assisted photocatalytic degradation of p-chlorophenol and rifampicin from aqueous solution using a novel g-C3N4 quantum dots incorporated α-MoO3 nanohybrid - Mechanism, pathway and toxicity studies.

In this work, a simple g-C3N4 quantum dots enriched MoO3 nanohybrid was formulated for the synergistic photocatalytic degradation of an industrially active organic pollutant, p-chlorophenol (PCP) and a widely prescribed antibiotic, rifampicin (RIF). The nanohybrid was synthesised via a facile ultrasonic assisted hydrothermal method and characterized using various characterization analysis. The efficient Z-scheme charge transfer of the nanohybrid resulted in the elimination of 98% PCP and 89% RIF under visible light with a rate constant of 0.012 and 0.006 min-1 respectively. The photocatalysis was attributed to the formation of both hydroxyl (OH•) and superoxide (O2•-) radicals in the resulting nanohybrid. The intermediates formed in the course of reaction were estimated through gas chromatography-mass spectroscopy/mass spectroscopy (GC-MS/MS) analysis and a suitable degradation pathway was constructed. The structural stability and reusability of the nanohybrid was affirmed through X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis to outweigh the industrial potential of the catalyst, with 85% PCP and 80% RIF removal efficiency after six cycles of degradation. In addition, the mineralization of the pollutants was confirmed by total organic carbon analysis. Further, the toxicity of the drug and the formed intermediates was determined using ecological structure activity relationships (ECOSAR) software. On the whole, this work provides an excellent insight for the development of environment-friendly materials in a large scale for the degradation of water-based pollutants.

Recent developments in architecturing the g-C3N4 based nanostructured photocatalysts: Synthesis, modifications and applications in water treatment.

Water pollution is becoming an inevitable problem in today's world. Tons and tons of wastewater with hazardous pollutants are getting discharged into the clean water bodies every day. In this regard, photocatalytic environmental remediation using nanotechnology such as the use of organic, metal and non-metal based semiconductor photocatalysts for photodegradation of pollutants has gained enormous attention in the past few decades. This review is focused particularly on graphitic carbon nitride (g-C3N4) which is a cheap, metal-free, polymeric photoactive compound and it is used as a potential photocatalyst in wastewater treatment. Though, pristine g-C3N4 is a good photocatalyst, it has certain drawbacks such as poor visible light absorption capacity, quicker recombination of photoelectrons and holes, delayed mass and charge transfer, etc. As a result, the pristine g-C3N4 catalyst is modified into novel 0D, 1D, 2D and 3D morphologies such as nano-quantum dots, nanorods, nanotubes, nanowires, nanosheets, nanoflakes, nanospheres, nanoshells, etc. It was also tailored into novel composites along with various compounds through doping, metal deposition, heterojunction formation, etc., to enhance the photocatalytic property of pure g-C3N4. The modified catalysts showed promising photocatalytic performance such as degradation of majority of pollutants in the environment. It also showed excellent results in the removal or reduction of heavy metals. This review provides a detailed record of g-C3N4 and its diverse photocatalytic applications in the past years and it provides knowledge for the development of such similar novel compounds in the future.

Efficacy of Brückner's Test for Screening of Refractive Errors by Non-ophthalmologist Versus Ophthalmologist: A Comparative Study.

OBJECTIVE: The aim of this study is to assess the efficacy of Brückner's test as a screening tool for identifying refractive errors by a non-ophthalmologist and to assess the inter-observer variation. SUBJECTS AND METHODS: This was a quasi-experimental study conducted at a tertiary care medical college hospital. Brückner's test was performed by a non-ophthalmologist followed by an ophthalmologist. The results were confirmed by cycloplegic refraction. RESULTS: The study included 75 children (31 males and 44 females) with a mean age of 13.3 ± 1.2 years. The results of Brückner's test by both non-ophthalmologist and ophthalmologist showed good sensitivity and specificity when compared with cycloplegic refraction. There was a good strength of agreement between the observations of non-ophthalmologist and ophthalmologist. CONCLUSION: Brückner's test is simple, quick, reliable, and easy to administer on children of all age groups that can provide information about the presence of refractive errors by using a coaxial light source such as direct ophthalmoscope. The application of this test by training primary care providers would be of immense value in the early identification of refractive errors.

Peripheral adenomatoid odontogenic tumour - is it really peripheral?: a case report.

A Peripheral Adenomatoid Odontogenic Tumour (PAOT) is quite a rare entity which has been infrequently reported in the literature. These uncommon clinical variants of an Adenomatoid Odontogenic Tumour (AOT), typically manifest as a soft tissue mass of the gingiva, which mimick a common epulis, but yet have an identical histopathologic presentation as their intraosseous counterpart. These lesions, though they are indolent in nature, have a tendency to cause well defined deep bony pockets. Only fourteen cases have been adequately documented so far. We are reporting a case of a PAOT of the anterior maxillary gingiva, with a periodontal bone defect in a 12 year old girl. The relevant literature has been briefly reviewed, with an insight into the probable origin of PAOTs with bony defects.