The GAO Materials Chemistry Research Group

The war in Ukraine has araised the global concern for possible chip shortage due to disruption in semiconductor-level neon supply. Being the world’s major neon supplier, Ukraine perfects the process of concentrating 18 ppm neon in air to 99.999% purity based on cryogenic fractionation. This kind of high-purity neon is used to trigger the 193 nm-deep ultraviolet wavelength for the state-of-the-art 7 nm spatial resolution photolithography, together with argon and fluorine in an excimer laser. The excited-state chemistry behind the argon-fluorine-neon excimer laser is explained in detail by Geoff, as well as why the neon is necessary during the process. See full story at Advanced Science News.

It is with great delight and excitement to announce that Professor Geoffrey Ozin is the 2022 Killam Prize winner for his leading work in nanoscience. The Killam Prizes are awarded by the Canada Council for the Arts and among Canada’s most prestigious prizes for careers in research, which is to “recognize and celebrate our most inspiring scholars and thought leaders.” Five awards are given, one each in the fields of humanities, social sciences, natural sciences, health sciences, and engineering. Each of the Laureates receive $100,000 in award funding.

The Banting Postdoctoral Fellowships program is a highly competitive and prestigious award designed to provide funding to the very best postdoctoral applicants, who will positively contribute to the country’s economic, social, and research-based growth. Typically, 70 fellowships per annual are awarded among more than 600 applicants from all over the world. The Solar Fuels Groups is pleased to announce Dr. Shufang among the few selected recipients.

To enhance the solar-to-chemical conversion efficiency of CO2 photocatalysis, light active materials need to be engineered into multiscale architectures that maximize photon capture and minimize optical losses. In this paper, Lourdes, Abhinav and coauthors developed a photocatalytic foam that helps achieve this goal by coating a uniform distribution and thickness indium oxide hydroxide nanorods film onto the internal surface of an oxidized nickel foam. Optimizing the size and density of pores of the photocatalytic foam enabled optimization of photochemical and thermochemical contributions to the rate for the solar reverse water gas shift. See full story at CEJ.

It remains a great challenge to overcome the intermittent and fluctuating sunlight for continuous photocatalytic fuels production. In this review, Joel and co-authors propose that persistent and memory-based photocatalysts, which efficiently operate under near zero light fluxes beyond sunset and during cloud intermittencies, are a potential solution to address and mitigate the challenge. Based on the idea of multivalent charge storage materials that allow charging during illumination and discharging to generate charge carriers upon post-illumination, this review describes examples of persistent photocatalysis systems, outlines the working mechanism, suggests strategies for performance optimization, proposes standardized Figures of Merit and discusses possible application scenes beyond solar fuels. See full story at AEM.

De-carbonizing the fossil-intensive chemicals and petrochemcials industries will help achieve a “net-zero” sustainable society. A recent report has targeted nitric acid production, an important feedstock for the production of dyes, pigments, nylon, explosives, and fertilizers. Currently, nitric acid is produced via catalytic ammonia synthesis and subsequent oxidation, but the high temperature and pressure (800-950°C, 12 atmospheres) and poor selectivity to NO lead to deleteriously high greenhouse gas CO2 and N2O emissions. In this work, a new two-step, chemical looping process has been invented which uses lattice oxygen instead of oxygen gas to oxidize NH3 to NO with increased selectivity (99.8%) and under milder reaction temperature (650 C). See full story at Advanced Science News.

Marketable, large-scale, and energy-efficient CO2 capture is essential for a net-zero future, which would be implemented at high-emitting locations, such as power plants, metal, cement, and chemical refineries. Liquid solvents such as amines, hydroxides, and organics, and metal oxide solids including alkali and alkaline earth oxides are typical absorbents, but they suffer from energy-intensive, non-selective dilemmas. How to develop an efficient material to overcome these problems remains the key challenge. Recently, the CALF-20, an intricate layered crystal composed of zinc, triazolate, and oxalate arranged in a 3D structure filled with nanometer-scale holes, has been used by Canadian company Svante in their revolutionary carbon capture process. A gram of this material has a massive surface area of 500 square meters, and the pores weakly yet preferentially bind CO2 over water. As a result, the CALF-20 displays selective CO2 physisorption at high capacities, retains it up to and beyond 40% RH with durability over 2000 h, and only requires modest amounts of energy to remove CO2. See full story at Advanced Science News.

It is with great excitement and delight that we wish to announce the Energy Materials Discovery: Enabling a Sustainable Future to be published by RSC in May, 2022 is now available for order on Amazon!

About the book: This book presents, through the eye of materials chemistry, an umbrella view of the myriad of classes of materials that make renewable energy technologies work. They are poised to facilitate the transition of non-renewable and unsustainable energy systems of the past into renewable and sustainable energy systems of the future. It is a story that often begins in chemistry laboratories with the discovery of new energy materials. Yet, to displace materials in existing energy technologies with new ones, depends not only on the ability to design and engineer a superior set of performance metrics for the material and the technology but also the requirement to meet a demanding collection of economic, regulatory, social, policy, environmental and sustainability criteria.

Artificial nitrogen reduction to ammonia is essential to life on earth, offering essential nitrogen elements for biomolecules, commodity, and fuel chemicals. The industrial Haber-Bosch process established in 1913 provides half of the fixed nitrogen in the global nitrogen cycle nowadays. However, high energy intensity, harsh reaction conditions, and extensive carbon footprint remain to be resolved. In a recent work, Lu, Yuping, and Geoff showcased an oxygen vacancy-laden tungsten oxide (WO3-x) catalyst that can facilitate electrochemical (EC) activation and fixation of the N2 molecule in thin air into ammonia in a neutral electrolyte. The EC conversion can be enabled via green electricity generated by a photovoltaic (PV) panel and the ammonia productivity can be further promoted by solar irradiation in a electrochemical cell (EC). A detailed energy and economic technical analyses demonstrate the PV-EC WO3-x system as a viable, stand-alone, modular, distributed ammonia generation system envisioned for the future green ammonia sustainable farm. See full story at Journal of Energy Chemistry.

Sunlight utilization is at the central of 21st century, being of fundamental importance to energy, environmental, climate and economy securities. However, the greatest challenge is known as the “duck curve” that depicts the mismatch between peak power demand and supply in the morning, evening and overcast days. This also applies to CO2 photocatalysis where continuous, instead of intermittent, production is favorable for potential industrial use. In the recent Nature Sustainability perspective, Dr. Loh and Prof. Ozin proposed a persistent CO2 photocatalysis scenario that could overcome the intermittent dilemma. The core idea is engineering a photocatalytic and charge-storing hybrid materials system that charges during the sunlight illumination while discharges to continue the charge carries-driven catalysis upon postillumination. In the perspective, the common strategies between catalytic engineering and charge storage engineering, various combinations of material candidates, as well as their interfacing structures are discussed in detail for CO2 hydrogenation of prolonged working period.