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1. Scalable nanomanufacturing of chalcogenide inks: a case study on thermoelectric V–VI nanoplates

   https://doi.org/10.1039/d1ta05858d  

   Zeng, Minxiang; Xie, Hongyao; Saeidi-Javash, Mortaza; Tanvir, A.N.M.; Du, Yipu; Chen, Jiahao; Kanatzidis, Mercouri G.; Zhang, Yanliang (October 2021, Journal of Materials Chemistry A)

   null (Ed.)

   Solution-processed semiconducting main-group chalcogenides (MMCs) have attracted increasing research interest for next-generation device technologies owing to their unique nanostructures and superior properties. To achieve the full potential of MMCs, the development of highly universal, scalable, and sustainable synthesis and processing methods of chalcogenide particles is thus becoming progressively more important. Here we studied scalable factors for the synthesis of two-dimensional (2D) V–VI chalcogenide nanoplates (M 2 Q 3  : M = Sb, Bi; Q = Se, Te) and systematically investigated their colloidal behaviour and chemical stability. Based on a solvent engineering technique, we demonstrated scale-up syntheses of MMCs up to a 900% increase of batch size compared with conventional hydrazine-based gram-level syntheses, and such a scalable approach is highly applicable to various binary and ternary MMCs. Furthermore, we studied the stability of printable chalcogenide nanoparticle inks with several formulation factors including solvents, additives, and pH values, resulting in inks with high chemical stability (>4 months). As a proof of concept, we applied our solution-processed chalcogenide particles to multiple additive manufacturing methods, confirming the high printability and processability of MMC inks. The ability to combine the top-down designing freedom of additive manufacturing with bottom-up scalable synthesis of chalcogenide particles promises great opportunities for large-scale design and manufacturing of chalcogenide-based functional devices for broad application. 

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2. Converting commercial Fe2O3 to effective anode material using glucose as “etching” agent

   https://doi.org/10.1016/j.ceramint.2023.07.234  

   Wang, Chenxu; Sireesha, Pedaballi; Shang, Jing; McCloy, John S.; Liu, Jin; Zhong, Wei-Hong (October 2023, Ceramics International)

   Fe2O3 is an appealing anode material due to its high specific capacity (1007 mAh g− 1), low cost, natural abundance, and nontoxicity. However, its unstable structure during cycling processes has hindered its potential. In this study, we present a “green” synthesis method to fabricate stable porous Fe2O3 encapsulated in a buffering hollow structure (p-Fe2O3@h-TiO2) as an effective anode material for Li-ion batteries. The synthesis process only involves glucose as an “etching” agent, without the need for organic solvents or difficult-to-control environments. Characterizations of the nanostructures, chemical compositions, crystallizations, and thermal behaviors for the intermediate/final products confirm the formation of p-Fe2O3@h-TiO2. The synthesized Fe2O3 anode material effectively accommodates volume change, decreases pulverization, and alleviates agglomeration, leading to a high capacity that is over eleven times greater than that of the as-received commercial Fe2O3 after a long cycling process. This work provides an attractive, “green” and efficient method to convert commercially abundant resources like Fe2O3 into effective electrode materials for energy storage systems. 

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3. Illuminating the Impact of Nonaqueous Solvents on Optical Trapping

   https://doi.org/10.1021/acs.jpcc.5c00640  

   Reynolds, Brandon; Crane, Matthew J (May 2025, The Journal of Physical Chemistry C)

   The optical trapping of colloidal semiconductor nanomaterials would enable single-particle photophysics, sensing, and chemical measurements. Yet, the trapping of these materials has lagged behind other dielectric and metallic materials due to the prevalence of aqueous solvents in optical trapping experiments, which are not suitable for many semiconductors. Here, we trap particles in multiple solvents and study the impact of nonaqueous solvents on optical trapping dynamics. These experiments and calculations show that there exists an optimal refractive index of the media that maximizes trapping strength and for colloidal nanomaterials a universal relationship to enhance trap strength. We also find that viscosity has no impact on the trap strength and changes only the residence times of particles in unstable traps. Trap stiffness measurements also show that photothermal effects, which are enhanced in nonaqueous solvents, can lead to convection, which modifies trap stiffnesses. These results provide an understanding of how solvent selection impacts trapping dynamics and general design rules for experiments in nonaqueous solvents, opening the door for improved sensing, chemistry, and photophysics studies using colloidal micro- and nanomaterials. 

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4. Toward affordable and sustainable use of precious metals in catalysis and nanomedicine

   https://doi.org/10.1557/mrs.2018.262  

   Xia, Younan; Zhao, Ming; Wang, Xue; Huo, Da (November 2018, MRS Bulletin)

   Precious metals represent some of the least abundant elements in the earth’s crust. There is an urgent need to maximize the utilization efficiency of these metals and thereby attain affordable and sustainable products. One approach for achieving this goal is based on the development of hollow nanocrystals with a well-controlled surface structure, together with a wall thickness kept below 2 nm, or roughly 10 layers of atoms. The hollow structure eliminates the waste of interior atoms and creates an inner surface, while the controllable surface structures contribute to the optimization of catalytic activity and selectivity. In this article, we begin with a brief introduction to two methods that have been developed for the synthesis of hollow nanocrystals: the first relying on the galvanic replacement with a sacrificial template, and the second involving layer-by-layer deposition of metal atoms followed by etching. We then showcase some remarkable properties and applications of this novel class of nanostructures, including their use as effective catalysts for energy conversion, photoresponsive carriers for controlled release and drug delivery, and theranostic agents. A discussion of the existing barriers to their commercialization is also presented. 

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5. In‐Plane Direct‐Write Assembly of Iridescent Colloidal Crystals

   https://doi.org/10.1002/smll.201905519  

   Tan, Alvin T. L.; Nagelberg, Sara; Chang‐Davidson, Elizabeth; Tan, Joel; Yang, Joel K. W.; Kolle, Mathias; Hart, A. John (December 2019, Small)

   Abstract Materials made by directed self‐assembly of colloids can exhibit a rich spectrum of optical phenomena, including photonic bandgaps, coherent scattering, collective plasmonic resonance, and wave guiding. The assembly of colloidal particles with spatial selectivity is critical for studying these phenomena and for practical device fabrication. While there are well‐established techniques for patterning colloidal crystals, these often require multiple steps including the fabrication of a physical template for masking, etching, stamping, or directing dewetting. Here, the direct‐writing of colloidal suspensions is presented as a technique for fabrication of iridescent colloidal crystals in arbitrary 2D patterns. Leveraging the principles of convective assembly, the process can be optimized for high writing speeds (≈600 µm s⁻¹) at mild process temperature (30 °C) while maintaining long‐range (cm‐scale) order in the colloidal crystals. The crystals exhibit structural color by grating diffraction, and analysis of diffraction allows particle size, relative grain size, and grain orientation to be deduced. The effect of write trajectory on particle ordering is discussed and insights for developing 3D printing techniques for colloidal crystals via layer‐wise printing and sintering are provided. 

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