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Graphitic carbon nitride (g‐CN) is a promising photocatalyst for solar fuel generation, but its charge carrier mobility, charge recombination, and CO2 reduction/H2 evolution efficacy and selectivity are a strong function of the synthesis and postsynthesis techniques employed. Protonation and phosphorous doping of g‐CN yield promise visible light activities, promoting enhanced CO2 reduction and hydrogen evolution. However, the amine‐functionalized surface chemistry of g‐CN gains little attention in open literature. Herein, g‐CN and phosphorus‐doped g‐CN are synthesized via facile one‐pot pyrolysis and subjected to protonation postsynthesis to quantify the influence of common strategies on surface amine content and photocatalyst activity for H2 evolution and CO2 reduction. Material characterization confirms the exfoliation of the photocatalyst and change in the amine functionalization of the surface. The amorphous phosphorus‐doped g‐CN material exhibits a high number of surface amine groups, increasing the adsorption prior to reduction and enhancing selectivity for CO2 reduction. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-CN) is a promising photocatalyst for solar fuel generation due to its medium band gap and facile synthesis from earth-abundant materials. However, low charge carrier mobility and high charge recombination have hampered the observed rate of H2 evolution and CO2 reduction. Herein, an electrostatically self-assembled 2D Z-scheme heterojunction between g-CN and bismuth vanadate (BiVO4) is investigated with and without reduced graphene oxide (rGO) acting as an electron transfer mediator to speed charge carrier mobility and hamper charge recombination. Protonation of the g-CN surface allow for self-assembly between 2D sheets of g-CN, rGO, and BiVO4. The mass ratio between g-CN and BiVO4 is incrementally adjusted to optimize synergistic charge transportation effects versus shadowing effects of multicomponent photocatalysts. Further, a selectivity effect is observed across mass ratios of photocatalyst constituents, allowing tuning of photocatalyst yield. [ABSTRACT FROM AUTHOR]

The selectivity of a sensor is the ability to discriminate the target from the interference molecules and display a target-specific sensor response. It is a critical trait for gas sensors that are used in real-time air pollution control, hazardous materials detection, food quality inspection and personal health monitoring. Attaining high target selectivity ensures that sensors will exhibit accurate information about the existence and concentration of a target gas, which is essential for reliable sensor response. To obtain target selectivity, it is critical to determine the optimum modification technique and receptor materials as well as to understand how each method works and how it could be designed for a specific target. For this purpose, in this review we present the working principles of the three leading chemical modification methods including catalyst decoration, composite formation, and surface functionalization, as well as the selection criteria of various recognition materials. Throughout the report, we offer a rich apprehension of these techniques by providing mechanistic insights, application areas, advantages, disadvantages, and plausible applications for the invention of the target-specific gas sensors. [ABSTRACT FROM AUTHOR]

Artificial photosynthesis is the process that converts solar energy and CO2 to valuable chemicals over a photocatalyst through CO2 photoreduction (CO2PR). Ordered mesoporous materials (OMMs) highly improve photocatalytic activity and exhibit superior mass transfer, owing to their extensive specific surface area and intense/ordered pore-network. This review provides a comprehensive guide to recent developments and the future prospects of ordered mesoporous (OM) photocatalysts with respect to CO2PR. The configuration of intrinsic (solely comprising compound semiconductors) and extrinsic (doped with heteroelements) OM-photocatalysts, their decorated counterparts with functional groups and Lewis acids/bases, and their composites with semiconductors, co-catalysts, and metal complexes together with their corresponding advantages for application to CO2PR are introduced. A rich understanding of these techniques is offered by reviewing the pore structures and reaction mechanisms. This article provides new insights and reflects on the research advances in OM-photocatalysts in CO2PR over the past two decades. [ABSTRACT FROM AUTHOR]