In order to allow quantum dots with the desired physical and chemical properties, the fine control and prediction of size during chemical syntheses is a challenge that must be addressed. In this work, we applied machine learning algorithms, with information extracted from scientific papers, to identify the most important variables in the synthesis of CdSe, CdS, PbS, PbSe, and ZnSe quantum dots. From the random forest and gradient boosting machine algorithms, the most influential parameters on the final diameter of the quantum dots were the time of reaction, temperature, and metal precursors. Our models were applied to suggest the best reaction parameters for a desired quantum dot size. This methodology shall contribute to the quantum dot community to save time and money while reaching the proper material conditions for their applications.

The sustainable synthesis of macromolecules with control over sequence and molar mass remains a challenge in polymer chemistry. By coupling mechanochemistry and electron‐transfer processes (i.e., mechanoredox catalysis), an energy‐conscious controlled radical polymerization methodology is realized. This work explores an efficient mechanoredox reversible addition‐fragmentation chain transfer (RAFT) polymerization process using mechanical stimuli by implementing piezoelectric barium titanate and a diaryliodonium initiator with minimal solvent usage. This mechanoredox RAFT process demonstrates exquisite control over poly(meth)acrylate dispersity and chain length while also showcasing an alternative to the solution‐state synthesis of semifluorinated polymers that typically utilize exotic solvents and/or reagents. This chemistry will find utility in the sustainable development of materials across the energy, biomedical, and engineering communities.

Ternary sulfide nanostructures are small band gap materials that combine relatively low toxicity with useful optical properties for several applications, including photovoltaics. A systematic experimental study on the synthesis and mechanism of formation of copper thioantimonates (Cu 3 SbS 4 ) and thioantimonides (CuSbS 2 ) nanoparticles is presented. Antimony oxide (Sb 2 O 3 ) was formed in an initial step by hydrolysis with oleylamine. The injection of a sulfur precursor led to the conversion to Cu 3 SbS 4 driven by an excess of sulfur in oleylamine medium and at high temperatures (>200 °C). The sulfur excess was depleted as the reaction progressed, causing the reduction of the antimony(V) of the Cu 3 SbS 4 back to antimony(III). Consequently, the Cu 3 SbS 4 was converted to CuSbS 2 . In addition, the rate of antimony reduction increased with the reaction temperature. The formation mechanism unveiled here provides important insights toward the synthesis of analogous materials.

We report ripening of metal particles anchored on pyramid-shaped heterostructure nanocrystals. The 'intra-particle' ripening results in a large metal tip at one corner with the other three tips vanishing. Investigation reveals that the ripening and core/shell formation affects photocatalytic activities via the Fermi level change.

We report the transformation of several metal selenide nanocrystals (NCs), including PbSe, CdSe, ZnSe, and PbSe/CdSe core/shell NCs, in dimethyl sulfoxide (DMSO) in acidic solutions at room temperature. In this study, the DMSO solution of metal selenide NCs was mixed with nitric acid, which was used to adjust the pH of the solution. Upon mixing, the metal selenide NCs readily transformed into crystalline selenium (trigonal structure) nano- or microwires under ambient light, whereas little or no transformation occurred in the dark. Photocorrosion, where the photogenerated carriers within the NCs participate in the cleavage of the metal and selenium atoms, turns out to be responsible for the transformation. DMSO removes organic ligands on the NC surface and creates surface trap sites for photoinduced charge carriers. Then, nitric acid helps shift the reduction potentials, thereby promoting a “cathodic reduction”. In this sense, the photocorrosion rate can be controlled by several parameters, such as the absorption cross section of the selenide NCs and the pH. The diameter and shape of the resulting selenium wires help gauge the transformation rate and thus unveil the transformation mechanism.