Nanoparticles and Nanomaterials: Faraday's Ruby Gold to Photocatalysis and Biomedical Innovations

Overview

This talk traces the development of nanoparticles from Faraday’s ruby gold and the birth of nanoscience to contemporary nanoscale materials and their use in functional technologies. It blends history with demonstrations and highlights collaborations between UCL and the Royal Institution.

Key insights

• Nanoparticles provide the color in ruby glass and underpin modern photocatalysis and surface science.
• Titanium dioxide coatings at the nanoscale can be transparent yet highly active as photocatalysts and as super hydrophilic surfaces.
• Spectroscopic enhancements using gold nanoparticles enable sensitive detection through PIRS and SIRS approaches.
• Real-world impact spans antimicrobial surfaces, radiative cooling coatings for buildings and capsules for imaging and therapy.

Introduction and historical context

The presentation begins with Michael Faraday's Buccarian Lecture on ruby gold, revealing the concept that gold can be divided into nanoscale particles. The speaker situates this within UCL's 200th anniversary and the long standing collaboration with the Royal Institution, noting joint chairs and programs that have advanced chemical and materials science.

The lecture then shifts to the nanoscale and outlines what constitutes a nanoparticle, using Faraday’s early descriptions to motivate today’s nanoscale materials and their diverse functions.

Titanium dioxide and photocatalysis

The talk highlights TiO2 as a photocatalyst and a surface modifier that renders surfaces hydrophilic and capable of degrading dirt under light exposure. The demonstration of Pilkington Active glass illustrates how a 25 nm TiO2 coating can dramatically alter wetting and photocatalytic properties. The float glass process and atmospheric pressure chemical vapor deposition APCVD are discussed as manufacturing routes that allow coatings to be formed directly on hot glass, enabling scalable production and commercial impact.

Strategies to improve TiO2 performance include nitrogen, sulfur, and phosphorus doping, multi layer stratified coatings, and heterojunctions between anatase and rutile. The talk also covers tungsten oxide–titania composites and core-shell designs that significantly boost photoactivity, supported by micrographs and elemental mapping data.

Beyond photocatalysis: devices and modeling

Computational modeling, particularly with the Catlow group, is used to explain electron and hole dynamics in photocatalysis. The collaboration with Peter Day and other RI-UCL connections are discussed as foundational to advancing materials chemistry and to creating scientific journals such as Journal of Materials Chemistry.

The speaker also discusses related nanostructured materials such as tungsten oxide and layered architectures that enhance charge separation and photocatalytic efficiency, along with critical observations about material design that enable real-world functionality.

Superhydrophobic surfaces and demonstrations

Superhydrophobic surfaces are demonstrated via racetrack experiments and treated textiles, with the lotus effect as a guiding principle. The demonstrations illustrate how rough nanoscale textures combined with low surface energy create droplets that bounce and roll, enabling self-cleaning properties and potential antimicrobial benefits. A tactile demonstration with untreated and Neverwet treated materials shows how water repellency can be scaled to practical surfaces including microscope slides and textiles.

Radiative cooling coatings

The talk presents nanoscale radiative cooling coatings called polycool, designed to emit heat in the mid infrared window to the cold universe, thereby cooling surfaces passively. The coatings are evaluated on water resistance, abrasion resistance, and hydrophobicity, and trials in Madrid, Singapore, and Adelaide are cited. The concept is illustrated with London bus trials and implications for energy efficiency in buildings and electric vehicles.

Healthcare and antimicrobial nanomaterials

Infections in healthcare settings motivate materials that can kill bacteria under ambient light. The presenter discusses using dyes and gold nanoparticles to create photoactivated antimicrobial surfaces, including practical product concepts such as catheter coatings and medical keyboards. The collaboration with Ondyne Biopharma and Endomagnetics demonstrates clinical translation of nanoparticle-based therapies for infection control and cancer diagnostics.

The talk closes with a note on magnetic nanoparticles for medical diagnostics and therapy, and reflects on the broader impact of RI and UCL collaborations in creating new technologies and companies while honoring the legacy of pioneers in nanoscience and catalysis.

Conclusion

Nanoparticles and nanomaterials permeate everyday life and high technology alike. The Royal Institution and University College London have cultivated a culture of collaboration and innovation, turning Faraday’s early insights into transformative technologies that touch energy, health, imaging and environmental sustainability.