Tech Doing Good

From cleaning up mountains of untreated sludge to making railway stations fully solar-powered, technology is an ally to those hoping to solve Asia’s environmental problems.

3. Renewable energy: A (photo)catalyst for a hydrogen future

‘Hydrogen fuel cell vehicles may be a greener alternative to the conventional petrol car, as only water is released as a by-product. However, hydrogen is mostly produced from the gasification of coal or natural gas, a process that still emits large quantities of carbon dioxide.

Photocatalysts use sunlight to turn water into hydrogen gas, but conventional photocatalysts are inefficient because they use ultraviolet light, which accounts for only three to four percent of the solar spectrum.

Led by Professor Tetsuro Majima from the Institute of Scientific and Industrial Research at Osaka University, Japan, a research team has invented a photocatalyst that is able to absorb a wider spectrum of light, including both visible and near-infrared light.

The catalyst is a composite of three components: ultrathin sheets of black phosphorous and lanthanum titanate embedded with gold nanoparticles. The black phosphorus and gold nanoparticles work as photosensitizers, the former responding to visible and near-infrared light, and the latter responding to visible light. The excited electrons move to the lanthanum titanate layers, leading to efficient hydrogen production from water by proton reduction.

Emission-free hydrogen production is a big part of Japan’s Basic Hydrogen Strategy, which envisions hydrogen fuel cell vehicles and industrial-scale hydrogen power generation plants becoming commonplace by 2050.

4. Renewable energy: Sunny projections for India’s railway network

The same coal-based power plants that fueled India’s industrial growth are now covering the country in a thick layer of smog. Looking towards a cleaner and brighter future, India’s government has set an ambitious target of 175 GW in renewable energy capacity by 2022, of which about 100 GW is planned for solar, 60 GW for wind and the rest for hydro and bio.

In July 2017, Indian Railways, the state-run transportation network, launched its first set of train coaches with rooftop solar panels that power the lighting systems, ceiling fans and information displays in cabins.

Although some railway stations across the country are already partially powered by solar and wind energy, the Guwahati railway station in Assam became in May 2018 the first railway station in India to be fully solar-powered, with grid-connected rooftop solar panels providing a capacity of 700 kW.

Indian Railways plans to generate around 1 GW of solar power by 2020 and 5 GW by 2025. Currently, it plans to embark on perhaps the ultimate challenge, of running the trains themselves, at least in part, from electricity generated from solar panels built along the tracks.

Lidao is a chemistry undergraduate at the University of Oxford, UK. An aspiring scientist, he is excited to learn about the latest discoveries and even more intrigued by the fascinating stories behind them. In his free time, he enjoys badminton, swimming and running around Singapore to uncover the best durian spots.

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