World’s smallest inorganic semiconductor ushers in the new era of eco-friendly hydrogen production

□ In collaboration with Professor Yoonjung Jang at the Department of Chemistry, Hanyang University, and Professor Stefan Ringe at the Department of Chemistry, Korea University, Professor Jiwoong Yang at the Daegu Gyeongbuk Institute of Science & Technology (DGIST; President Kunwoo Lee) has successfully produced eco-friendly solar hydrogen for the first time in world history based on a quantum semiconductor nanocluster, which is the world’s smallest inorganic semiconductor material.

□ Professor Yang’s research team has achieved a stable nanocluster of cadmium selenide consisting of 26 atoms ((CdSe)₁₃), a sub-1-nm ultrasmall quantum semiconductor material that has never been previously used as a photocatalyst, in a water environment, applied it as a photocatalyst to successfully produce hydrogen, and suggested its potential for new applications across various fields, including not only energy and environment but also quantum science.

□ The quantum semiconductor nanocluster consisting of a specific number of atoms is a unique material located at the boundary between molecules and nanocrystals. While high reactivity as a catalyst is expected because most of its atoms are exposed on the surface, it is difficult to use it in practical applications due to its structural instability and poor electrical properties.

□ In this context, his research team designed and fabricated a superstructure in which a quantum nanocluster is self-arranged and bonded three-dimensionally, and obtained structural stability. By cross-linking between ligands on the surface of the cluster, they achieved a stable structure while maintaining the properties of individual clusters. In addition, his team doped cobalt ions (Co²⁺) within the cluster to enhance electrical properties and effectively induced photocatalytic hydrogen evolution.

□ “This study is the first of its kind to demonstrate that a quantum semiconductor nanocluster, known as the smallest inorganic semiconductor structure in existence, can be used as a photocatalyst,” said Professor Jiwoong Yang at DGIST. “In the future, it is expected to expand into various possibilities in not just energy and environment but also quantum science.”

□ Meanwhile, this study was funded by the National Research Foundation of Korea and the Korea Institute for Advancement of Technology, and its results were published online in April in Nano Letters, one of the world’s most authoritative journals in nanochemistry.