Carbonitride aerogels mediate the photocatalytic conversion of water

August 4, 2017, Wiley
Carbonitride aerogels mediate the photocatalytic conversion of water
Credit: Wiley

Nanochemistry meets macrostructures: Chinese scientists report the synthesis of a macroscopic aerogel from carbonitride nanomaterials which is an excellent catalyst for the water-splitting reaction under visible-light irradiation. The study published in the journal Angewandte Chemie adds new opportunities to the material properties of melamine-derived carbonitrides.

Melamine can be polymerized with formaldehyde to give a highly durable and light resin, but it can also condensed to form nanostructures of carbonitride . These assemblies made of carbon and nitrogen combine the honeycomb-like electronically active network of graphene with some extra functionality of nitrogen. Searching for ways to assemble these nanostructures into a stable macroscopic architecture, Xinchen Wang and his team at Fuzhou University in China have now prepared a catalytically highly active and stable lightweight material, which serves well in artificial photosynthesis and offers very interesting structural and electronic properties.

Aerogels are gels but without water—up to ninety-nine percent of their structure is air. This porosity gives them a huge surface ideal for catalytic or sensory application. As carbonitrides are materials with very interesting nanostructure and graphene-like properties but nitrogen functionality, it has long be sought to bring them into a controlled macroscopic assembly. "Since CN is rich in nitrogen-containing groups, it is expected that CN may have interesting assembly behaviors like proteins or peptides in biological systems," the authors said.

The enhanced surface area and higher number of catalytic sites would make these aerogels highly functional macroscopic materials. Employing only physical interparticle forces intrinsic to the nanoparticles, the scientists prepared the aerogel by making a colloidal aqueous solution of carbonitride nanoparticles to settle first into a hydrogel, then converting it into a stable aerogel by a conventional freeze-drying technology. "This method has several advantages, including scalability for mass production and low cost," the authors said. In combination with a platinum co-catalyst, the was much better a photocatalyst for hydrogen evolution than the bulk carbonitride, and hydrogen peroxide was generated from pure water under visible-light irradiation when the bulk carbonitride failed.

Thus, by joining forces of chemical and physical characteristics from the nano- to the macroscale, they have created a new lightweight material with excellent catalytic prospects. This promising application of melamine building blocks points the way forward to new materials, and is far apart from the well-established mass production of the light and durable, but not so thermostable melamine plastic dishes.

Explore further: Plant inspiration could lead to flexible electronics

More information: Honghui Ou et al. Carbon Nitride Aerogels for the Photoredox Conversion of Water, Angewandte Chemie International Edition (2017). DOI: 10.1002/anie.201705926

Related Stories

Plant inspiration could lead to flexible electronics

June 21, 2017

Versatile, light-weight materials that are both strong and resilient are crucial for the development of flexible electronics, such as bendable tablets and wearable sensors. Aerogels are good candidates for such applications, ...

Ruthenium rules for new fuel cells

June 28, 2017

Rice University scientists have fabricated a durable catalyst for high-performance fuel cells by attaching single ruthenium atoms to graphene.

Aerogel catalyst shows promise for fuel cells

March 2, 2015

(Phys.org)—Graphene nanoribbons formed into a three-dimensional aerogel and enhanced with boron and nitrogen are excellent catalysts for fuel cells, even in comparison to platinum, according to Rice University researchers.

Recommended for you

Nanoscale Lamb wave-driven motors in nonliquid environments

March 19, 2019

Light driven movement is challenging in nonliquid environments as micro-sized objects can experience strong dry adhesion to contact surfaces and resist movement. In a recent study, Jinsheng Lu and co-workers at the College ...

OSIRIS-REx reveals asteroid Bennu has big surprises

March 19, 2019

A NASA spacecraft that will return a sample of a near-Earth asteroid named Bennu to Earth in 2023 made the first-ever close-up observations of particle plumes erupting from an asteroid's surface. Bennu also revealed itself ...

The powerful meteor that no one saw (except satellites)

March 19, 2019

At precisely 11:48 am on December 18, 2018, a large space rock heading straight for Earth at a speed of 19 miles per second exploded into a vast ball of fire as it entered the atmosphere, 15.9 miles above the Bering Sea.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.