Green synthesis of rectangular hollow tubular carbon nitride via in-situ self-assembly strategy to enhance the degradation of tetracycline hydrochloride under visible light irradiation.

It has been an urgent requirement for materials with remarkable performance in the photocatalytic degradation of organic contaminants by photocatalytic technology. Limited surface area and speedy recombination rate of photogenerated charge carriers seriously restrain the application of g-C3N4. Morphology control is a powerful approach to enhance the photocatalytic efficiency of g-C3N4. Herein, we reported a method to attain graphitic carbon nitride with rectangular hollow tubular morphology and asperous surface (TUM-CN-2) which is prepared from urea-melamine hydrothermal products and trithiocyanuric acid by self-assembling without using organic solvents or template agents. The specific surface area, photocatalytic activity, and photo-generated carriers migration and separation rate of the obtained photocatalyst TUM-CN-2 are vastly improved. Contrasted with pure g-C3N4, the degradation rate of tetracycline hydrochloride (TCH) and Rhodamine B (RhB) was enhanced about 3.04 and 13.96 times in visible light irradiation, respectively. Moreover, the interference parameters, active free radicals, potential degradation mechanism, and degradation paths of TCH were researched systematically. This work provides a green way to acquire the modified g-C3N4 with splendid catalytic activity through the self-assembly method.

Transparent Electrothermal Film Defoggers and Antiicing Coatings based on Wrinkled Graphene.

Fog, frost, ice, and other natural phenomena can inevitably affect human life and the function of equipment. Therefore, removal or prevention is an urgent problem to be solved. As a new type of 2D material, graphene possesses great application potential in defogging and antiicing. In this work, a graphene film with intentionally increased defects and uniformly distributed wrinkles is synthesized on copper-zinc alloy substrates by chemical vapor deposition, and transparent electrothermal film defoggers are prepared based on such material. The defoggers can completely remove fog within 5 s when supplying a safe voltage of 28 V. The surface resistance of the defoggers is sensitive to humidity and it can monitor the defogging process in real time. Such outstanding performance is attributed to the ultrafast evaporation mechanism, which can prevent excessive water accumulation. The antiicing performance of wrinkled graphene (WG) is further studied. The antiicing coatings can delay freezing for 1.25 h at -15 °C or 2.8 h at -10 °C. The superior performance of WG can be explained by its unique surface structure and nanoscale roughness. Taken together, WG is expected to be used in antifog glass, rearview mirror defogging, aircraft surface deicing, and other applications.

Macro van der Waals p-n heterojunction based on SnSe and SnSe2.

Van der Waals (vdW) heterojunctions based on two-dimensional materials have attracted great attention in emerging photoelectronics. However, the low-efficiency growth of single crystals significantly limits the practical applications of vdW heterojunctions. Here, we report a macro SnSe/SnSe2 heterojunction assembled by conformally transferring in-plane p-type SnSe on n-type SnSe2 synthesized by chemical vapor deposition. With well-matched band alignments, the SnSe/SnSe2 vdW photodetector exhibits dramatically enhanced performance with a responsivity of 17.5 mA W-1 and a response time of 17 ms, comparing with the sole SnSe or SnSe2 based photodetector.

Highly Stretchable, Adaptable, and Durable Strain Sensing Based on a Bioinspired Dynamically Cross-Linked Graphene/Polymer Composite.

Flexible strain sensors can detect physical signals (e.g., temperature, humidity, and flow) by sensing electrical deviation under dynamic deformation, and they have been used in diverse fields such as human motion detection, medical care, speech recognition, and robotics. Existing sensing materials have relatively low adaptability and durability and are not stretchable and flexible enough for complex tasks in motion detection. In this work, a highly flexible self-healing conductive polymer composite consisting of graphene, poly(acrylic acid) and amorphous calcium carbonate is prepared via a biomineralization-inspired process. The polymer composite shows good editability and processability and can be fabricated into stretchable strain sensors of various structures (sandwich structures, fibrous structures, self-supporting structures, etc.). The developed sensors can be attached on different types of surfaces (e.g., flat, cambered) and work well both in air and under water in detecting various biosignals, including crawling, undulatory locomotion, and human body motion.

Formation of Uniform Water Microdroplets on Wrinkled Graphene for Ultrafast Humidity Sensing.

Portable humidity sensors with ultrafast responses fabricated in wearable devices have promising application prospects in disease diagnostics, health status monitoring, and personal healthcare data collecting. However, prolonged exposures to high-humidity environments usually cause device degradation or failure due to excessive water adsorbed on the sensor surface. In the present work, a graphene film based humidity sensor with a hydrophobic surface and uniformly distributed ring-like wrinkles is designed and fabricated that exhibits excellent performance in breath sensing. The wrinkled morphology of the graphene sensor is able to effectively prevent the aggregation of water microdroplets and thus maximize the evaporation rate. The as-fabricated sensor responds to and recovers from humidity in 12.5 ms, the fastest response of humidity sensors reported so far, yet in a very stable manner. The sensor is fabricated into a mask and successfully applied to monitoring sudden changes in respiratory rate and depth, such as breathing disorder or arrest, as well as subtle changes in humidity level caused by talking, cough and skin evaporation. The sensor can potentially enable long-term daily monitoring of breath and skin evaporation with its ultrafast response and high sensitivity, as well as excellent stability in high-humidity environments.

The physics and chemistry of graphene-on-surfaces.

Graphene has demonstrated great potential in next-generation electronics due to its unique two-dimensional structure and properties including a zero-gap band structure, high electron mobility, and high electrical and thermal conductivity. The integration of atom-thick graphene into a device always involves its interaction with a supporting substrate by van der Waals forces and other intermolecular forces or even covalent bonding, and this is critical to its real applications. Graphene films on different surfaces are expected to exhibit significant differences in their properties, which lead to changes in their morphology, electronic structure, surface chemistry/physics, and surface/interface states. Therefore, a thorough understanding of the surface/interface properties is of great importance. In this review, we describe the major "graphene-on-surface" structures and examine the roles of their properties and related phenomena in governing the overall performance for specific applications including optoelectronics, surface catalysis, anti-friction and superlubricity, and coatings and composites. Finally, perspectives on the opportunities and challenges of graphene-on-surface systems are discussed.

Correction: The physics and chemistry of graphene-on-surfaces.

Correction for 'The physics and chemistry of graphene-on-surfaces' by Guoke Zhao, Xinming Li, Meirong Huang et al., Chem. Soc. Rev., 2017, 46, 4417-4449.

Extranodal NK/T-Cell Lymphoma Predominantly Composed of Anaplastic Cells: A Frequently Misdiagnosed and Highly Aggressive Variant.

Extranodal NK/T-cell lymphoma (ENKTL) is a non-Hodgkin lymphoma associated with the Epstein-Barr virus that primarily affects individuals in East Asia and indigenous populations in Central and South America. Morphologically, ENKTL typically consists of medium-sized cells or a combination of small and large cells. This report presents 10 cases characterized by predominantly anaplastic cells with diffuse expression of CD30, resembling anaplastic lymphoma kinase-negative anaplastic large cell lymphoma (ALK-negative ALCL) and demonstrating highly aggressive behavior. The cohort included 9 males and 1 female, ranging in age from 29 to 65 years (median age: 47 y). Eight patients presented with nasal disease, while 2 had non-nasal disease. Five patients had stage I/II disease, and the remaining 5 had stage III/IV disease. Morphologically, necrosis was observed in 9 cases, angiocentric-angiodestructive growth in 3 cases, and pseudoepitheliomatous hyperplasia in 2 cases. Anaplastic cells predominated in all cases, with some displaying eccentric, horseshoe-shaped, or kidney-shaped nuclei (referred to as "Hallmark" cells). The morphology profile was monomorphic in 3 cases and polymorphic in 7 cases. Immunohistochemically, all cases tested positive for cytotoxic granule markers (TIA1 and granzymeB) and Epstein-Barr virus-encoded RNA. Cytoplasmic expression of CD3ε and CD56 was observed in 9 of 10 cases. Interestingly, most cases (7 of 8) exhibited variable expression of MuM1, ranging from 10% to 90%. All cases showed diffuse positivity for CD30 but were negative for ALK, resulting in 3 cases being initially misdiagnosed as ALK-negative ALCL. Compared with nonanaplastic cases, anaplastic cells predominant ENKTL had a significantly higher frequency of "B" symptoms, bone marrow involvement, hemophagocytic lymphohistiocytosis, and higher Ki67 proliferative index. These findings provide valuable information for pathologists, expanding their understanding of the cytologic spectrum of ENKTL. This rare variant of ENKTL, characterized by the predominance of anaplastic cells and diffuse CD30 expression, exhibits high aggressiveness and should be differentiated from ALK-negative ALCL. Awareness of this uncommon variant is crucial in preventing misdiagnosis and ensuring the timely initiation of therapy.

A triple-channel sensor array utilizing fluorescent carbon dots for simultaneous discrimination and detection of multiple fluoroquinolones.

The presence of fluoroquinolones (FQs) residues in food and the environment has prompted concerns regarding food safety and public health. Consequently, it is of great significance to analyze the types and levels of FQs present. However, the majority of studies have concentrated on the specific detection of individual FQs, with a notable absence of high-throughput and rapid analysis methods for the simultaneous detection of multiple FQs that may coexist in food and the environment. Hereon, a triple-channel sensor array was successfully constructed utilizing fluorescent carbon dots (TA-CDs), with the assistance of Cu2+ and Fe3+, for the qualitative discrimination and quantitative detection of eight types of FQs. The sensor array can distinguish between different concentrations of FQs and various mixtures of FQs, as well as 100 % accuracy in the discrimination of unknown samples. Impressively, the sensor platform can quantitatively detect FQs in animal-derived foods, such as honey, milk, eggs, and pork, as well as in water samples. This research has the potential to be extended to other analytes with similar chemical structures or properties.

Synthesis of Double Defects in g-C3 N4 to Enhance the H2 O2 Production by Dual-Electron O2 Reduction.

In this work, the graphitic carbon nitride with -C≡N defects and S-defects (N2 -SCN-4) was constructed. The H2 O2 production efficiency of N2 -SCN-4 was 1423.3 µmol g-1 h-1 under the visible light (λ≥420 nm) irradiation, which was 15.4 times that of pristine g-C3 N4 . The -C≡N groups promote the adsorption of H+ and the S-defects provide the active center for the adsorption and activation of O2 . Furthermore, the surface morphology, microstructure, and photoelectric chemical properties of samples were investigated by a series of characterizations, and the response range of N2 -SCN-4 to visible light increases obviously. Meanwhile, the efficiency of photo-produced charge separation and the selectivity of H2 O2 production were discussed in detail. The experimental and characterization results confirmed that the charge separation efficiency and the selectivity of the 2e- O2 reduction reaction (ORR) were improved under the synergistic effect of the double defects. This work provides a strategy for improving the photocatalytic performance of photocatalysts.