KIST Develops World's First Autonomous Aquatic Robot That Removes Algae Using Only Sunlight [Reading Science]

On-site Hydrogen Peroxide Production Using Only Air and Water;
No Need for External Power or Chemical Transport

Up to 1,760 Times Faster Algae Removal Than Commercial Hydrogen Peroxide;
Demonstration at Dams and Reservoirs Anticipated

A world-first autonomous floating robot capable of removing recurring summer algae blooms using only sunlight has been developed. By instantly producing and spraying hydrogen peroxide—a green algae removal agent—on-site using only air and water, the robot enables long-term autonomous operation without the need for external power supply or chemical transportation. This innovation is expected to be adopted as an eco-friendly water quality management technology for large-scale water bodies such as dams and reservoirs.

Operating Principle and Performance of the Solar-Powered Autonomous Floating Robot. (Left) The process of generating electricity using solar power and producing hydrogen peroxide on-site by utilizing oxygen from the air and water to remove algae blooms. The inset photo shows the key catalyst that produces hydrogen peroxide. (Top right) The appearance of algae-contaminated water becoming clear after 6 hours of robot operation. (Bottom right) Comparative results showing that the hydrogen peroxide produced on-site by the robot removes algae blooms much faster than commercial hydrogen peroxide. Provided by the research team.

The Korea Institute of Science and Technology (KIST) announced on July 31 that a research team led by Dr. Oh Hyungseok of the Clean Energy Research Center, together with Dr. Kim Namdong of the Quantum Materials and Superconductivity Research Center, and Dr. Cho Hyesung of the Extreme Materials Research Center, has jointly developed the world’s first autonomous floating remediation robot powered solely by sunlight without the need for external power.

Algae blooms occur repeatedly in rivers and lakes during summer months, causing foul odors and depleting underwater oxygen, which results in mass fish deaths. Certain cyanobacteria also produce toxins that can threaten drinking water safety, which is why there has been a constant demand for more effective removal technologies.

On-site Hydrogen Peroxide Production

Traditional approaches to algae removal have typically involved workers spraying hydrogen peroxide directly from boats. However, this method requires repeat coverage of large areas, demanding significant manpower and cost. Furthermore, stabilizers added for long-term storage reduce the efficiency of algae removal.

Structure and Operating Principle of Water Purification Device. (Top Left) Schematic diagram of the internal structure of a device that continuously purifies contaminated water. (Bottom Left) Real-time purification of green algae-contaminated water passing through the device. (Right) Principle of converting oxygen in the air into hydrogen peroxide as a catalyst to decompose green algae. Provided by the research team

The research team developed a “single-atom catalyst,” dispersing individual cobalt atoms onto a carbon substrate, to synthesize hydrogen peroxide on-site using just air and water. Hydrogen peroxide generated with this technology was verified to remove algae blooms up to 1,760 times faster than commercially available hydrogen peroxide.

The team integrated this catalyst system with solar panels and floating devices to produce an autonomous floating robot. The robot utilizes electricity generated by solar panels during the day, allowing it to operate autonomously both day and night. In pilot operations at the KIST pond, the robot’s algae removal performance was successfully validated.

This technology holds strong potential for use in dams, reservoirs, and other areas lacking power infrastructure. Since hydrogen peroxide can be produced on-demand at the site, transportation costs and leakage risks associated with chemicals are reduced. Moreover, scaling up the device could enable its application at rivers, large-scale water sources, and diverse water quality management sites in the future.

Photo of the research team. From the left, Youngrok Lee, Postdoctoral Researcher (First Author / KIST Clean Energy Research Center), Minwoo Kim, Student Researcher (First Author / KIST Quantum Materials and Superconductivity Research Center), Chulwoo Oh, Postdoctoral Researcher (First Author / Former KIST Clean Energy Research Center), Sangmin Oh, Student Researcher (First Author / Former KIST Extreme Materials Research Center), Namdong Kim, Principal Researcher (Corresponding Author / KIST Quantum Materials and Superconductivity Research Center), Hyesung Cho, Principal Researcher (Corresponding Author / KIST Extreme Materials Research Center), Hyungseok Oh, Principal Researcher (Corresponding Author / KIST Clean Energy Research Center). Provided by KIST

Oh Hyungseok, Principal Researcher at KIST, stated, “This achievement is the result of integrating water purification catalysts, advanced composite materials, and robotic control technology. We hope that this technology, which enables on-site production of algae removal agents using only sunlight, will serve as a new alternative for next-generation smart water management.”

This study was supported by the Ministry of Science and ICT through KIST’s core programs, the carbon upcycling project, and the National Research Council of Science and Technology’s creative convergence research initiative. The findings have been published in the latest issue of the international journal ‘Applied Catalysis B: Environment and Energy,’ which covers the fields of environment and energy.

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