Nano-titanium dioxide (TiO2) is one of the most commonly used materials being synthesized for use as one of the top five nanoparticles. Due to the extensive application of TiO2 nanoparticles and their inclusion in many commercial products, the increased exposure of human beings to nanoparticles is possible. This exposure could be routed via dermal penetration, inhalation and oral ingestion or intravenous injection. Therefore, regular evaluation of their potential toxicity and distribution in the bodies of exposed individuals is essential. Keeping in view the potential health hazards of TiO2 nanoparticles for humans, we reviewed the research articles about studies performed on rats or other mammals as animal models. Most of these studies utilized the dermal or skin and the pulmonary exposures as the primary routes of toxicity. It was interesting that only very few studies revealed that the TiO2 nanoparticles could penetrate through the skin and translocate to other tissues, while many other studies demonstrated that no penetration or translocation could happen through the skin. Conversely, the TiO2 nanoparticles that entered through the pulmonary route were translocated to the brain or the systemic circulation from where these reached other organs like the kidney, liver, etc. In most studies, TiO2 nanoparticles appeared to have caused oxidative stress, histopathological alterations, carcinogenesis, genotoxicity and immune disruption. Therefore, the use of such materials in humans must be either avoided or strictly managed to minimise risks for human health in various situations.

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The use of graphene‐based composite as anti‐corrosion and protective coatings for metallic materials is still a provocative topic worthy of debate. Nickel–graphene nanocomposite coatings have been successfully fabricated onto the mild steel by electrochemical co‐deposition technique. This research demonstrates the properties of nickel–graphene composite coatings influenced by different electrodeposition current densities. The effect of deposition current density on the; surface morphologies, composition, microstructures, grain sizes, mechanical, and electrochemical properties of the composite coatings are executed. The coarseness of deposited coatings increases with the increasing of deposition current density. The carbon content in the composite coatings increases first and then decreases by further increasing of current density. The improved mechanical properties and superior anti‐corrosion performance of composite coatings are obtained at the peak value of current density of 9 A dm−2. The incorporation of graphene sheets into nickel metal matrix lead to enhance the micro hardness, surface roughness, and adhesion strength of produced composite coatings. Furthermore, the presence of graphene in composite coating exhibits the reduced grain sizes and the enhanced erosion–corrosion resistance properties.

Hierarchical CoFe-LDH@g-C3N4 heterostructures have been synthesized via a facile and easily scalable in situ solvothermal method for efficient overall water splitting.

The development of durable, low-cost, and efficient photo-/electrolysis for the oxygen and hydrogen evolution reactions (OER and HER) is important to fulfill increasing energy requirements. Herein, highly efficient and active photo-/electrochemical catalysts, that is, CoMn-LDH@g-C N hybrids, have been synthesized successfully through a facile in situ co-precipitation method at room temperature. The CoMn-LDH@g-C N composite exhibits an obvious OER electrocatalytic performance with a current density of 40 mA cm at an overpotential of 350 mV for water oxidation, which is 2.5 times higher than pure CoMn-LDH nanosheets. For HER, CoMn-LDH@g-C N (η =-448 mV) requires a potential close to Pt/C (η =-416 mV) to reach a current density of 50 mA cm . Furthermore, under visible-light irradiation, the photocurrent density of the CoMn-LDH@g-C N composite is 0.227 mA cm , which is 2.1 and 3.8 time higher than pristine CoMn-LDH (0.108 mA cm ) and g-C N (0.061 mA cm ), respectively. The CoMn-LDH@g-C N composite delivers a current density of 10 mA cm at 1.56 V and 100 mA cm at 1.82 V for the overall water-splitting reaction. Therefore, this work establishes the first example of pure CoMn-LDH and CoMn-LDH@g-C N hybrids as electrochemical and photoelectrochemical water-splitting systems for both OER and HER, which may open a pathway to develop and explore other LDH and g-C N nanosheets as efficient catalysts for renewable energy applications.