Photocatalytic Degradation of Natural Organic Matter

Natural Organic Matter (NOM) comprises a heterogeneous assemblage of humic and fulvic substances derived from the decomposition of plant and microbial material. Elevated levels of NOM in surface and groundwater pose challenges for drinking water treatment, notably through the formation of harmful disinfection by-products. Photocatalytic degradation harnesses semiconductor materials—most commonly titanium dioxide (TiO₂), zinc oxide (ZnO) and more recently emerging ferrites and doped composites—to generate reactive oxygen species (ROS) under ultraviolet or visible irradiation. These ROS, including hydroxyl and superoxide radicals, attack and mineralise organic macromolecules to carbon dioxide, water and inorganic salts. Advances in catalyst design have focused on band-gap engineering, surface area enhancement and hybridisation with carbonaceous supports to extend light absorption into the visible range and improve quantum efficiency. Hybrid processes combining adsorption and photocatalysis, solar-driven reactors and scale-up considerations are also under active development. Analytical metrics such as dissolved organic carbon removal, excitation–emission matrix fluorescence and total organic halide assays are employed to assess efficacy. The global significance of photocatalytic NOM degradation lies in its potential to deliver energy-efficient, low-chemical-footprint water treatment solutions, mitigate public health risks and enable water reuse in agriculture and industry.

Research from Nature Portfolio

No recent studies in leading portfolio journals specifically addressing photocatalytic degradation of natural organic matter have been identified in the past two years.

Photocatalytic Degradation of Natural Organic Matter publication trend

The graph below shows the total number of articles in photocatalytic degradation of natural organic matter across all publications each year (not limited to Nature Index journals).

Technical terms

Natural Organic Matter (NOM): A complex mixture of organic molecules originating from plant and microbial decomposition in aquatic environments.

Photocatalysis: Acceleration of chemical reactions by a light-activated catalyst that generates reactive species upon photon absorption.

Reactive Oxygen Species (ROS): Short-lived radicals such as hydroxyl (•OH) and superoxide (•O₂⁻) that oxidise organic contaminants.

Band Gap: Energy interval between the valence and conduction bands of a semiconductor that determines its light-absorption threshold.

Heterogeneous Photocatalyst: A solid-phase catalyst that facilitates photoreactions in a separate phase from the reactants, enabling easy recovery and reuse.

References

1. Photocatalytic Oxidation of Natural Organic Matter in Water. Water (2021).
2. Efficient removal of humic acid in water using a novel TiO 2 composite with biochar doping. RSC Advances (2022).
3. Novel Electrochemical Preparation of N-Doped TiO2/Graphene for Enhanced Stability and Photocatalysis Degradation of Humic Acid. Sustainability (2022).