The sustainable manufacturing of nanoparticles (NPs) has become critical to reduce life cycle energy use and the associated environmental impact. With the ever-growing production volume, titanium dioxide (TiO 2 ) NPs have been produced through various synthesis routes with differing input materials and reactions, which result in differential reactivity, crystallinity, surface areas, and size distributions. In this study, life cycle assessment is used to analyze and compare the environmental impact of TiO 2 NPs produced via seven routes covering physical, chemical, and biological syntheses. The synthesis routes are chosen to represent mainstream NP manufacturing and future trends. Mass-, surface area-, and photocatalytic reactivity-based functional units are selected to evaluate the environmental impact and reflect the corresponding changes. The results show that impact associated with the upstream production of different precursors are dominant for the chemical route. Compared to the chemical route, the physical route requires substantial quantities of supporting gas and highenergy inputs to maintain high temperature; therefore, a higher environmental burden is generated. A high environmental burden is also modeled for the biological route due to the required bacterial culture media. This present study aims to identify the most efficient synthesis route for TiO 2 NP production, lower the potential environmental impact, and improve green synthesis and sustainability.

This paper described the optical properties of CdSe and CdSe/CdS nanoparticles, synthesized by the microemulsion method followed by refluxing in toluene/methanol (60:1). Both optical spectroscopy and structural characterization (XPS, XRD, and HRTEM) suggested the core/shell structure of CdSe/CdS samples. Most notable in this work was that capping CdSe nanoparticles with CdS materials yielded a strong narrow band-edge luminescence, indicating a successful passivation by removing surface deep trap luminescence. Proper surface modification with cadmium ions resulted in the further enhancement of the photoluminescence quantum yields of the CdSe and CdSe/CdS nanoparticles. The XPS data confirmed the elemental composition of the CdSe and CdSe/CdS nanoparticles. The CdSe and CdS diffraction patterns exhibited peak positions corresponding to those of their bulk wurtzite crystal structures. Experimental SectionChemicals. Cadmium chloride, sodium sulfide, toluene, thiophenol, triethylamine, pyridine, and methanol were all of the highest quality commercially available.

It is very challenging to effectively exfoliate and functionalize hexagonal boron nitride (h-BN). Here, an efficient exfoliation and functionalization of bulk h-BN was carried out by a ball-milling method using boric acid (BA) as a lubricant and modifier. A series of boric-acid-functionalized boron nitride nanosheets (BNNSs) was successfully produced using this approach. The obtained BNNS thermostable suspension can be easily condensed into a jelly-like dispersion with ultra-high concentration, up to 90 mg ml −1 . The eco-friendly BA was readily and easily recyclable and remarkably reusable during the BNNS exfoliation. Interestingly, by means of a differential-centrifugation technique, the BNNSs could be easily separated and screened with different sizes and thicknesses. These screened BNNS samples also exhibited different levels of functionalization. As a result, filtration membranes made of various well-screened BNNSs exhibited an obviously different rejection rate for pollutant in water. In addition, the different screened BNNS products show a variable ability to dielectric behavior due to their different-level functionalization. We believe that our created boric-acidfunctionalized BNNSs, combined with the smartly screened separation by differential centrifugation, can broaden the future practical applications of BNNS materials.