Deep-ocean hydrothermal systems host unique habitat for living organisms at the seafloor and provide carbon and energy sources to the deep biosphere. In this research (funded by NSF CAREER), we seek understanding of the hydrothermal chemistry and interconversion mechanisms of organic functional groups, and also the roles of minerals and dissolved metals in the origin, transport, and degradation of organic carbon and nitrogen in oceanic hydrothermal systems. See Aspin et al. (2025); Liao et al. (2025); Aspin et al. (2023); Liao et al. (2021); Fu et al. (2020a); Yang et al. (2018) for example.

This area of research (funded by MSGC/NASA and NSF) investigates the prebiotic synthesis of biomolecule precursors such as amino acids, amides, and peptides, with a goal of improving our understanding and prediction of habitability on early Earth and other worlds. See Chen et al. (2026); Brown et al. (2026); Aspin et al. (2025); Robinson et al. (2021); Fu et al. (2020b); Fu et al. (2020c) for example.

With mechanistic understanding of hydrothermal geochemistry, we aim to deploy sustainable methods of using Earth-abundant inorganic materials as clean, cost-effective, and novel catalysts for green chemical synthesis and applications. We also explore new frontiers of geoscience research that could be used toward addressing current challenges in industrial processing and environmental remediation. See Brown et al. (2026); Liao et al. (2022); Fu et al. (2020a); Yang et al. (2015) for example.

Our new direction of research (funded by OU DIG) focuses on the recycling of waste materials such as plastics and biomass through emerging hydrothermal techniques such as hydrothermal carbonization. Our developed method avoids using toxic organic solvent or expensive catalysts, by utilizing water as the only reaction medium, and Earth-abundant materials as green and selective catalysts. See Aspin et al. (2026) for example.

Accumulation and degradation of soil organic carbon are subject to climatic impact through both biological and weathering processes. We utilize a combination of analytical and statistical methods to identify the abundance and distribution of soil organic matter, by which we can identify the key biogeochemical drivers and pathways in natural systems such as the Arctic tundra. See Chen et al. (2024); Wen et al. (2023);  Philben et al. (2020); Yang et al. (2019); Chen et al. (2018); Yang et al. (2017); Yang et al. (2016a) for example.

This NSF-funded project aims to develop low-cost, sensitive, and robust soil sensors for carbon dioxide and methane detection in tundra and permafrost soils. We use ionic liquid as a unique solvent and electrolyte to develop miniaturized and multimodal electrochemical gas sensors that can function at sub-zero temperatures in the Arctic. See Sridhar et al. (2023) as an example.

Sand dunes along the Great Lakes shorelines provide unique habitats for rare plants and animal species and host thriving microbial communities. In this project (funded by ORISE and DOE), we aim to examine and understand the biogeochemical processes that are related to carbon cycling, phosphorus uptake, and mercury methylation in these world's largest freshwater sand dune ecosystems. See Zaporski and Yang (2022); Zaporski et al. (2020) for example.

Mercury (Hg) is a well-known pollutant in the air, soils, rivers, lakes, and oceans. Its methylated form, methylmercury (MeHg), is a more potent neurotoxin that can cause severe neurological damage to humans. Our goal is to understand the formation, transport, and degradation of MeHg in ecosystems such as Arctic tundra, the Great Lakes, and cropland, as well as estimate the potential of microbial methylation in those environments. See Hao et al. (2025); Liu et al. (2023); Zhang et al. (2022); Dai et al. (2021); Zaporski et al. (2020); Yang et al. (2016b) for example.

Plume ejection could influence relative abundances of biosignatures in geysering ocean worlds such as Saturn's moon Enceladus. This project (funded by RCSA Scialog and NASA Exobiology) aims to measure the fractionation of biosignatures in a laboratory-simulated plume system. The collected information would be useful to interpret the relative abundance and distribution of biosignatures in the subsurface ocean for future search-for-life measurements. See Neveu, Aspin et al. (2024) for example.

Searching for potential and promising biosignatures could provide compelling evidence for presence of life beyond Earth. Biologically produced methylated gases such as CH3Cl and CH3Br are promising biosignature candidates for life detection. In this project (funded by The Kavli Foundation), we aim to investigate the Hg methylation potential under relevant exoplanetary atmospheres. We conduct laboratory-simulated experiments and combine with photochemical models to evaluate the applicability of using methylated Hg as a potential biosignature for remote detection on exoplanets.