A groundbreaking advancement in the field of sustainable energy and chemical production has been achieved by a research team led by Assistant Professor Shogo Mori and Professor Susumu Saito at Nagoya University. Their pioneering work in artificial photosynthesis offers a promising method to generate energy and valuable organic compounds from waste materials using sunlight and water. Published in Nature Communications, this development represents a major step toward addressing global energy challenges and advancing sustainable chemical production processes.
Artificial photosynthesis, as the name suggests, mimics the natural process of photosynthesis that occurs in plants. In nature, plants convert sunlight, carbon dioxide, and water into glucose, which serves as energy. Scientists have long aimed to replicate this process to produce energy and valuable chemicals in a similar manner. The new technique developed by the Nagoya University team builds on this concept but takes it a step further by using organic waste products as raw materials, rather than relying on carbon dioxide, which is typically considered an abundant but challenging resource in the artificial photosynthesis process.
As Professor Susumu Saito explains, the key breakthrough in their research lies in the fact that their process produces not only energy but also useful chemicals, without generating harmful waste products like carbon dioxide. “In artificial photosynthesis, chemical reactions are designed to replicate the way plants convert sunlight, water, and carbon dioxide into energy-rich glucose. However, the waste products that are typically formed during traditional chemical processes are not produced in our method. Instead, we are generating energy and valuable organic compounds,” Saito notes.
The technique developed by the team is called artificial photosynthesis directed toward organic synthesis (APOS), and it represents a significant paradigm shift in artificial photosynthesis research. Unlike conventional artificial photosynthesis, which typically relies on carbon dioxide and sometimes organic compounds, APOS uses organic waste and water as its raw materials. This innovation is poised to revolutionize how we think about the synthesis of useful organic compounds and energy production from renewable resources.
One of the most remarkable aspects of this new method is the cooperation between two types of inorganic semiconductor photocatalysts. These photocatalysts play a critical role in promoting two important reactions: the decomposition of organic waste materials and water splitting, which leads to the generation of hydrogen. This collaboration between photocatalysts facilitates the synthesis of valuable organic compounds and “green” hydrogen, a clean form of energy that can be harnessed for a variety of applications.
“The success of APOS lies in the interaction between two different photocatalysts, which promote the decomposition of organic waste materials while splitting water to generate hydrogen. This process allows us to create useful organic compounds and generate hydrogen without producing harmful byproducts like carbon dioxide,” explains Professor Saito. The ability to synthesize useful chemicals such as alcohols, ethers, and even pharmaceutical analogs from waste materials is a significant advantage of this technique. It opens the door to developing a more sustainable chemical production process, where waste materials are upcycled into valuable products.
In their experiment, the researchers demonstrated the ability to synthesize over 25 distinct alcohol and ether compounds, each with different functional groups, from a variety of organic raw materials. Among the products were compounds with medical applications, including an analog of an antidepressant and a compound related to a drug used to treat hay fever. These results underscore the potential of this method to contribute to the sustainable production of not only chemicals but also pharmaceutical materials.
Another notable aspect of the APOS method is its ability to modify existing organic compounds to improve their properties. In the study, the researchers successfully modified a drug used to treat elevated lipid levels in the blood, showcasing the versatility and practicality of their technique. This capability is particularly promising in the pharmaceutical industry, where modifying existing compounds to enhance their efficacy or reduce side effects is a critical area of research.
The implications of this breakthrough extend beyond just the pharmaceutical industry. As Professor Saito points out, their technique could potentially help reduce waste and avoid the formation of carbon dioxide, a major greenhouse gas. One example of how their method can be applied involves acetonitrile, a byproduct of industrial processes used in the mass production of polymers and carbon nanofibers. Traditionally, acetonitrile is discarded as waste, but using it as a raw material in APOS transforms it into a valuable product, reducing waste and making the process more sustainable.
“This is a perfect example of how APOS can turn a waste product into something useful. Acetonitrile is often generated during industrial processes, but our method allows it to be upcycled into a valuable compound, which could help reduce waste in various industries,” Saito explains.
The potential applications of this artificial photosynthesis technique are vast. By utilizing renewable resources such as sunlight and water, APOS offers a more sustainable and environmentally friendly approach to chemical production, as compared to traditional methods that rely on fossil fuels and generate harmful emissions. The ability to synthesize a wide range of organic compounds, including pharmaceutical materials, provides an exciting opportunity for industries looking to shift toward more sustainable practices while meeting the growing global demand for chemicals and medicines.
Furthermore, this method aligns with the broader goals of reducing greenhouse gas emissions, mitigating climate change, and addressing resource scarcity. By utilizing waste materials as raw resources, the APOS technique could help reduce the environmental impact of industrial processes while simultaneously addressing waste management challenges.
This breakthrough also has the potential to contribute significantly to the agricultural sector. With the ability to produce useful chemicals from waste products, APOS could be applied to the synthesis of fertilizers, pesticides, and other agricultural chemicals. Given the growing demand for sustainable farming practices and reduced chemical inputs, this technique could play a key role in advancing green chemistry in agriculture.
While the findings of this research are still in the early stages, the potential for APOS to transform how we produce chemicals, pharmaceuticals, and energy from renewable resources is clear. The work of Professor Saito and his team marks the beginning of a new era in artificial photosynthesis research, one that holds promise for addressing the complex challenges of sustainability and resource management in the 21st century.
This research aligns with the broader efforts to develop green technologies that reduce our dependence on non-renewable resources and minimize environmental impact. As the world continues to face pressing challenges related to climate change, waste management, and energy sustainability, innovative solutions like APOS offer a glimpse of a future where chemical production is not only efficient but also sustainable and environmentally responsible.
Looking forward, the researchers hope to refine and expand their technique, with the ultimate goal of scaling it up for industrial applications. They also aim to explore new ways to improve the efficiency of the process and increase the range of organic compounds that can be synthesized through APOS. By continuing to push the boundaries of artificial photosynthesis, the Nagoya University team is paving the way for a more sustainable and environmentally conscious future, where waste is minimized, energy is harnessed from renewable sources, and valuable chemicals are produced without the harmful byproducts that have traditionally plagued chemical manufacturing processes.
More information: Nature (2025). DOI: 10.1038/s41467-025-56374-z