A guided-inquiry project designed to teach students the basics of spectrophotometric instrumentation at the second year level is presented. Students design, build, program, and test their own single-wavelength, submersible photometer using low-cost light-emitting diodes (LEDs) and inexpensive household items. A series of structured prelaboratory assignments guide students through the processes of researching background information, designing a photometer device, and developing their own procedure to test the performance of the device. Students also learn basic skills of data acquisition by programming an easy-to-use LabVIEW interface for their device. Using a colorimetric indicator dye, students use their photometers and LabVIEW interfaces to determine the endpoint of an acid–base titration and compare the linear response of their device against that of a commercially available spectrophotometer. Students who completed the experiment indicated that the experience improved their understanding of spectroscopy, as well as their critical thinking skills and research ability.

A detailed investigation of the photochemical etching of silicon nanocrystals (Si-NCs) in aqueous hydrofluoric acid (HF) mixtures is described. By increasing the HF concentration and lowering the pH upon addition of hydrochloric acid (HCl), oxide-embedded Si-NCs were rapidly etched, and photoluminescence (PL) from the resulting hydride-terminated Si-NCs tailored from the near-IR to the yellow/green spectral region by irradiating the reaction mixture at the desired PL wavelength. These results are consistent with a hole-driven etching pathway rather than the chemically induced oxidation/etch pathway commonly exploited for Si nanostructures. The relationship among NC size, polydispersity, and PL was investigated using small-angle X-ray scattering. We suggest the defect density of Si-NCs is a crucial parameter for effective size control via photochemical exciton-mediated HF etching. Improved HF etching methods are expected to enable Si-NC applications through the realization of narrow polydispersity and PL bandwidth.

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Following the declaration of COVID-19 as a pandemic by the World Health Organization, The University of British Columbia shifted their instruction to online delivery. This communication describes the foundational principles used in two courses: first-year Introductory Chemistry and upper-year Materials Chemistry, to navigate this transition. The authors outline their efforts to apply these principles effectively in the context of the differing logistical needs. Throughout this work, student perceptions obtained from course-specific survey data collected at the end of the January–April 2020 term are underlined. Lastly, this work summarizes our plans for remote content delivery in the fall of 2020.

Portions of classic undergraduate quantitative analysis experiments in complexiometric titration and potentiometry are combined with a field-sampling experience to create a two period (2 × 3 h) comparison-based experiment for second-year students. A multifunctional chemical analysis device is used with calcium ion-selective electrode for field measurement of calcium concentration in seawater. The results are compared with later simultaneous potentiometric and colorimetric titration with ethylenediaminetetraacetic acid (EDTA). Students compare precision, difficulty, and sources of error of the different methods and present a written argument supporting their choice of best method including advantages and limitations. The experiment provides an introduction to chemistry in-the-field, sample collection and handling, complex matrices, imperfect methods, fallibility of instrumentation, real-world performance, and decision-making.