CaCu3Ti4O12/CNT nanocomposite for enhanced photocatalytic seawater splitting to hydrogen generation

Abstract

Calcium copper titanate (CaCu3Ti4O12- abbreviated as CCTO) is a widely researched material with exceptional electrical and dielectric properties, making it promising for large-scale semiconductor manufacturing owing to its environmentally friendly, robust nature and relatively low cost. In this report, a scalable CCTO and their hybrid composite with carbon nanotubes (CNTs) is synthesized through a two-step ultrasonic sol-gel mixing method and is tested for hydrogen production from the sea and distilled water under artificial solar visible light. The combine the intrinsic UV activity of titanium in CCTO with the visible light absorption capabilities of CNTs, leading to synergistically enhanced photocatalytic performance (PC) which is confirmed by both experimental and computational results. After 4 h of unsullied water and seawater hydrogen generation, the CCTO with 0.3 M and 0.2 M CNT concentration achieved 0.584 and 0.568 mmol/g/h, respectively, with AQY values of 5.51 % and 5.40 %. The highest measured consistent photocurrent was measured at CCTO/CNT 0.3 M which proves its efficient charge transfers and stability over time which agree with electron impedance and Nyquist data. Enhanced charge transfers and improved photoresponse by the CCTO/CNT composite enables effective migration of the photogenerated electrons from the CNT to the CCTO catalytic sites and suppressing electron-hole recombination. This interaction highlights the merit of the material toward visible-light-driven CCTO/CNT photocatalysis and photoelectrochemical processes. © 2025 Hydrogen Energy Publications LLC