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Pristine titanium dioxide (TiO2) changes color from white to black when it is reduced from TiIV to TiIII by photoexcited electrons. However, the black coloration requires substantial light energy to create, and it vanishes instantaneously upon exposure to air. This work reports the synthesis of surface‐functionalized N‐doped TiO2 nanocrystals that rapidly change color (i.e., within seconds) from whitish to black under low‐power irradiation with excellent color stability in atmospheric conditions. The N‐doping plays a critical role in promoting the surface‐adsorption of polyol groups to stabilize the TiIII species and accelerate the coloration process. A rewritable paper fabricated using these nanocrystals exhibits excellent writing and erasing reversibility in response to UV irradiation and oxygen exposure. The low‐cost, rapid response, excellent reversibility, and good color stability are vital advantages of N‐doped TiO2 nanocrystals for color‐switching applications. [ABSTRACT FROM AUTHOR]

The fast and reversible switching of plasmonic color holds great promise for many applications, while its realization has been mainly limited to solution phases, achieving solid‐state plasmonic color‐switching has remained a significant challenge owing to the lack of strategies in dynamically controlling the nanoparticle separation and their plasmonic coupling. Herein, we report a novel strategy to fabricate plasmonic color‐switchable silver nanoparticle (AgNP) films. Using poly(acrylic acid) (PAA) as the capping ligand and sodium borate as the salt, the borate hydrolyzes rapidly in response to moisture and produces OH− ions, which subsequently deprotonate the PAA on AgNPs, change the surface charge, and enable reversible tuning of the plasmonic coupling among adjacent AgNPs to exhibit plasmonic color‐switching. Such plasmonic films can be printed as high‐resolution invisible patterns, which can be readily revealed with high contrast by exposure to trace amounts of water vapor. [ABSTRACT FROM AUTHOR]

Herein, we show that copper nanostructures, if made anisotropic, can exhibit strong surface plasmon resonance comparable to that of gold and silver counterparts in the near‐infrared spectrum. Further, we demonstrate that a robust confined seeded growth strategy allows the production of high‐quality samples with excellent control over their size, morphology, and plasmon resonance frequency. As an example, copper nanorods (CuNRs) are successfully grown in a limited space of preformed rod‐shaped polymer nanocapsules, thereby avoiding the complex nucleation kinetics involved in the conventional synthesis. The method is unique in that it enables the flexible control and fine‐tuning of the aspect ratio and the plasmonic resonance. We also show the high efficiency and stability of the as‐synthesized CuNRs in photothermal conversion and demonstrate their incorporation into nanocomposite polymer films that can be used as active components for constructing light‐responsive actuators and microrobots. [ABSTRACT FROM AUTHOR]

Pristine titanium dioxide (TiO2) changes color from white to black when it is reduced from TiIV to TiIII by photoexcited electrons. However, the black coloration requires substantial light energy to create, and it vanishes instantaneously upon exposure to air. This work reports the synthesis of surface‐functionalized N‐doped TiO2 nanocrystals that rapidly change color (i.e., within seconds) from whitish to black under low‐power irradiation with excellent color stability in atmospheric conditions. The N‐doping plays a critical role in promoting the surface‐adsorption of polyol groups to stabilize the TiIII species and accelerate the coloration process. A rewritable paper fabricated using these nanocrystals exhibits excellent writing and erasing reversibility in response to UV irradiation and oxygen exposure. The low‐cost, rapid response, excellent reversibility, and good color stability are vital advantages of N‐doped TiO2 nanocrystals for color‐switching applications. [ABSTRACT FROM AUTHOR]

Corrosion poses safety and operational challenges in the oil and gas field, particularly in a sour environment. Corrosion inhibitors (CIs) are thus employed to protect the integrity of industrial assets. However, CIs have the potential to dramatically impair the effectiveness of other co-additives, such as kinetic hydrate inhibitors (KHIs). Here, we propose an acryloyl-based copolymer, previously used as a KHI, as an effective CI. The copolymer formulation provided a corrosion inhibition efficiency of up to 90% in a gas production environment, implying that it can reduce or even eliminate the need for an additional dedicated CI in the system. It also demonstrated a corrosion inhibition efficiency of up to 60% under field-simulated conditions for a wet sour crude processing environment. Molecular modeling suggests that the enhanced corrosion protection is imparted by the favorable interaction of the heteroatoms of the copolymer with the steel surface, potentially displacing adhered water molecules. All in all, we show that an acryloyl-based copolymer with dual functionalities can potentially overcome issues caused by incompatibilities in a sour environment, resulting in significant cost savings and operational ease., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Pristine titanium dioxide (TiO 2 ) changes color from white to black when it is reduced from Ti IV to Ti III by photoexcited electrons. However, the black coloration requires substantial light energy to create, and it vanishes instantaneously upon exposure to air. This work reports the synthesis of surface-functionalized N-doped TiO 2 nanocrystals that rapidly change color (i.e., within seconds) from whitish to black under low-power irradiation with excellent color stability in atmospheric conditions. The N-doping plays a critical role in promoting the surface-adsorption of polyol groups to stabilize the Ti III species and accelerate the coloration process. A rewritable paper fabricated using these nanocrystals exhibits excellent writing and erasing reversibility in response to UV irradiation and oxygen exposure. The low-cost, rapid response, excellent reversibility, and good color stability are vital advantages of N-doped TiO 2 nanocrystals for color-switching applications., (© 2022 Wiley-VCH GmbH.)

Nanocomposites containing FeS as catalyst and MoS 2 as cocatalyst have been synthesized toward efficient heterogeneous Fenton reaction. The deposition of FeS nanoparticles in situ on the surface of MoS 2 nanosheets creates strong contact between the two components and generates a large number of exposed Mo 6+ sites and sulfur vacancies, which contribute to the enhanced degradation rate by accelerating Fe 3+ /Fe 2+ cycling and ensuring rapid electron transfer. In addition, the MoS 2 /FeS nanocomposite catalysts exhibit the best performance at near-neutral conditions (pH 6.5), which solves the challenges in conventional Fenton reactions such as leaching of metal ions, the formation of iron slurry, and the need of adjusting solution pH. Further, the nanocomposite can maintain high efficiency after many recycling experiments. It is believed that the MoS 2 /FeS nanocomposite represents an efficient heterogeneous Fenton catalyst that can greatly promote the performance of advanced oxidation processes (AOPs) for solving practical environmental issues.

Conventional colloidal syntheses typically produce nanostructures with positive curvatures due to thermodynamic preference. Here, we demonstrate the creation of surface concavity in Au nanorods through seed-mediated growth in confined spaces and report their thermochromic responses to temperature changes. The unique surface concavity is created by templating against Fe 3 O 4 nanorods, producing a new concavity-sensitive plasmonic band. Due to the high surface energy, the metastable nanorods can be reconstructed at a moderate temperature, enabling convenient and precise tuning of their plasmonic properties by aging in different solvents. Such structural reconstruction of concave Au nanorods enables the fabrication of thermochromic plasmonic films that can display images with vivid color changes or exhibit encrypted, invisible information upon aging. This templating strategy is universal in creating concave nanostructures, which may open the door to designing new nanostructures with promising applications in sensing, anticounterfeiting, information encryption, and displays.

Herein, we show that copper nanostructures, if made anisotropic, can exhibit strong surface plasmon resonance comparable to that of gold and silver counterparts in the near-infrared spectrum. Further, we demonstrate that a robust confined seeded growth strategy allows the production of high-quality samples with excellent control over their size, morphology, and plasmon resonance frequency. As an example, copper nanorods (CuNRs) are successfully grown in a limited space of preformed rod-shaped polymer nanocapsules, thereby avoiding the complex nucleation kinetics involved in the conventional synthesis. The method is unique in that it enables the flexible control and fine-tuning of the aspect ratio and the plasmonic resonance. We also show the high efficiency and stability of the as-synthesized CuNRs in photothermal conversion and demonstrate their incorporation into nanocomposite polymer films that can be used as active components for constructing light-responsive actuators and microrobots., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)