We developed quantum dot (QD)‐sensitized hybrid TiO 2 nanocomposite photoanodes consisting of titanium‐based MXene (Ti 3 C 2 T x ) and titanium nitride (TiN) to promote synergy between the transport efficiency of MXenes and the plasmonic properties of TiN nanoparticles (NPs), toward enhancing the performance of photoelectrochemical (PEC) water splitting. MXenes sheets were synthesized at room temperature through delamination of an aluminum layer of the MAX phase of titanium aluminum carbide (Ti 3 AlC 2 ), and subsequently, nano‐sized dot‐like TiN NPs were incorporated through sonication and hydrothermal reaction. The PEC system based on the optimized TiO 2 ‐MXene‐TiN (MXene:TiN 1:4 wt%) hybrid network sensitized with CdS/CdSe/ZnS QDs yields a high photocurrent density of 15.80 mA cm −2 (at 1.0 V vs. the reversible hydrogen electrode RHE) under 1 sun illumination (AM 1.5G, 100 mW cm −2 ), which is almost double (~119%) as compared to the control TiO 2 /QDs device (7.20 mA cm −2 ). This significant enhancement in current density is attributed to the plasmonic effect of TiN NPs, improved charge carrier mobility and reduced recombination losses arising from the incorporated MXene sheets. This improvement in charge transport directly contributes to higher device efficiency, as demonstrated by faster transient voltage decay rates and prolonged carrier lifetimes in our measurements.
Bansal et al. (2026) studied this question.