That leaves it so incomplete about its topic that the link should be replaced with a better one if possible.
But even if the capture negligible, the negative-sign is still interesting - it's teased in the headline! And when a headline teases something, it owes us an explanation of where the carbon goes, a key part of the story to anyone with a middle-school-level understanding of 'carbon'.
Barring nuclear reactions or alchemical magic, it's impossible that "its only byproduct is water". The carbon has to collect somewhere.
Science journalism like this makes its readers dumber.
The problem isn't where the C goes, it's the dismal efficiency