By Dr. Shanthi Prabha V (Scientist and Research Coordinator, Advanced Centre of Environmental Studies and Sustainable Development (ACESSD), Mahatma Gandhi University)

The potential of Biochar-Derived Carbon Dots (BCCDs) in transforming the agricultural landscape is significant. Nano-biochar materials, including BCCDs, have drawn considerable attention due to their unique properties and wide-ranging environmental applications. BCCDs, characterized by their size of less than 10 nm and distinctive fluorescence properties, are particularly promising. These nanomaterials are derived from low-value biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More waste biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More through various methods such as hydrothermal carbonization (HTC), microwave-hydrothermal techniques, and pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More.

HTC utilizes high temperature and pressure to convert biomass into BCCDs, while microwave-hydrothermal methods offer narrow size distribution using microwaves, and pyrolysis involves heating a carbon source to produce BCCDs ranging from 0.4 to 2.0 nm. BCCDs hold great potential in agriculture, offering benefits such as soil health monitoring, crop growth enhancement, and pest control. This could lead to improved crop yields, sustainable farming practices, and enhanced soil fertility, thus revolutionizing agricultural practices globally.

BCCDs possess numerous advantages, including a green synthesis process, photoluminescence, biocompatibility, enhanced surface properties, porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More, water solubility, and low toxicity. These characteristics make them suitable for biosensing, biomedicine, and photocatalysis applications, among others. In agriculture, the abundance of BCCD’s surface functional groups like amino, carboxyl, and hydroxyl renders them water-soluble and capable of binding to various substances, making them highly effective in agricultural applications.

For instance, invasive aquatic weeds like Eichhornia can be converted into biochar and further processed into carbon dots through hydrothermal conversion, repurposing the weed into valuable nanomaterials for agricultural use. Several characterization techniques, including UV light, Transmission Electron Microscopy (TEM), and Photoluminescence Absorbance (PLA) measurements, are used to study the properties of BCCDs.

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Characterization of BCCD: (a) Photoluminescence (PL) spectrum  and (b) TEM image of BCCD from Eichhornia confirms the formation of carbon dots

BCCDs play a multifaceted role in enhancing plant growth and soil health. They create a conducive environment for seed germination, stimulate root elongation and branching, improve nutrient absorption and photosynthesis, and enhance chlorophyll production and photosynthetic efficiency. Furthermore, they stimulate the natural defense mechanisms of plants, serve as a source of carbon and nutrients for beneficial soil microorganisms, and contribute to soil fertility and health.

Understanding the application effects and mechanisms of BCCDs in plants, especially crops, is crucial for developing innovative, sustainable cultivation techniques that enhance crop growth and yield. The team of experts, consisting of Ms. Giya Merline Kuriakose, Ms. Amalu Suresh, Ms. Sashaika Sajan, and Ms. Shanty Chelekkattil Benny, affiliated with the Advanced Centre of Environmental Studies and Sustainable Development at Mahatma Gandhi University in Kerala, India, is presently investigating the potential of biochar-derived carbon dots in the soil-plant system, focusing mainly on carbon sequestration and greenhouse gas dynamics. The data presented here are derived from the ongoing work. This type of research is vital in safeguarding global food security amid escalating agricultural complexities.

N.B. This article is based on ongoing biochar research through Advanced Centre of Environmental Studies and Sustainable Development (ACESSD), Mahatma Gandhi University, Kerala, India and in collaboration with Giya Merline Kuriakose, Amalu Suresh, Sashaika Sajan, Shanty Chelekkattil Benny, and Soya Parveen KS.

Dr. Shanthi Prabha V is a Research Scientist at the Advanced Centre of Environmental Studies and Sustainable Development (ACESSD), Mahatma Gandhi University, Kerala, India. Passionate about biochar, she has dedicated the last 15 years to intensive research in this field alongside her robust team. Together, they have published numerous papers and are continuously engaged in innovative projects aimed at leveraging biochar for environmental sustainability, soil health enhancement, and climate change mitigation.