Excessive release of greenhouse gas carbon dioxide (CO2) into the atmosphere and continuous utilization of fossil fuels has resulted in global warming and energy shortage. Among the different alternatives, photocatalytic conversion of CO2 to fuels and hydrogen production is a promising approach. To achieve this goal, highly efficient and low-cost semiconductor are demanding to maximize solar energy conversion to renewable fuels. In this perspective, metal free two-dimensional (2D) graphitic carbon nitride (g-C3N4) has attracted numerous considerations because of its low cost and higher reduction potential, but it has a lower efficiency. Herein, we demonstrated various engineering defect strategies in g-C3N4 to promote photocatalytic efficiency under solar energy. Initially, an overview of engineering defects, creation of different vacancies in g-C3N4, and their identification is discussed. In the main stream defect, engineering such as carbon, nitrogen, and oxygen to promote g-C3N4 photocatalytic efficiency is systematically disclosed. Subsequently, the role of sulfur (S) and phosphorus (P) atoms in g-C3N4 to maximize CO2 reduction and hydrogen production are deliberated. The comparative analysis, efficiency enhancement, and role of defect engineering are finally discussed to get higher yields and productivities under solar energy utilization. 

Defect Engineering in Graphitic Carbon Nitride Nanotextures for Energy Efficient Solar Fuels Production: A Review

Insight into the morphology and crystal growth of DL-methionine in aqueous solution with presence of cellulose polymers

As an emerging class of flexible materials, mechanically bendable molecular crystals are broadly classified as elastic or plastic. Nevertheless, flexible organic crystals with mutually exclusive elastic and plastic traits, with contrasting structural requirements, co-existing under different stress settings are exceptional; hence, it is imperative to establish the concurring factors that beget this rare occurrence. We report a series of halogen-substituted benzil crystals showing elastic bending (within ∼2.45% strain), followed by elastoplastic deformation under ambient conditions. Under higher stress settings, they display exceptional plastic flexibility that one could bend, twist, or even coil around a capillary tube. X-ray diffraction, microscopy, and computational data reveal the microscopic and macroscopic basis for the exciting co-existence of elastic, elastoplastic, and plastic properties in the crystals. The layered molecular arrangement and the weak dispersive interactions sustaining the interlayer region provide considerable tolerance towards breaking and making upon engaging or releasing the external stress; it enables restoring the original state within the elastic strain. Comparative studies with oxalate compounds, wherein the twisted diketo moiety in benzil was replaced with a rigid and coplanar central oxalate moiety, enabled us to understand the effect of the anisotropy factor on the crystal packing induced by the C 
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 O⋯C tetral interactions. The enhanced anisotropy depreciated the elastic domain, making the oxalate crystals more prone to plastic deformation. Three-point bending experiments and the determined Young's moduli further corroborate the co-existence of the elastic and plastic realm and highlight the critical role of the underlying structural elements that determine the elastic to plastic transformation. The work highlights the possible co-existence of orthogonal mechanical characteristics in molecular crystals and further construed the concurrent role of microscopic and macroscopic elements in attaining this exceptional mechanical trait.

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Flexible organic crystals. Understanding the tractable co-existence of elastic and plastic bending

Crystal Growth of l-Alanine with Glycine-Based Oligopeptides: The Revelation for the Competitive Mechanism

Coarse-grained pseudoboehmite was obtained by neutralization of an ammonium aluminum sulfate solution [NH4Al(SO4)2·12H2O] with ammonia water [NH3 (aq)] in the presence of sodium dodecylbenzene sulf...

Effect of SDBS on Crystallization Behavior of Pseudoboehmite

Growth defects of organic crystals: A review

Pyridoxine hydrochloride, commonly known as vitamin B6 (VB6), is considered to be one of the most essential vitamin enhancers. Understanding its crystal morphology is of paramount interest in the p...

Fei Liu

Papers

Growth defects of organic crystals: A review

Uncovering the Role of Surfactants in Controlling the Crystal Growth of Pyridoxine Hydrochloride

Crystal Growth of l-Alanine with Glycine-Based Oligopeptides: The Revelation for the Competitive Mechanism