Many researchers have found positive effects upon inserting carbon nanostructures (CNTs, GO, CDs) in TiO2 for environmental photocatalysis, dye-sensitized photovoltaics, and photoelectrochemical (PEC) applications. Benefits of carbon nanostructures are generally linked to their outstanding properties of charge mobility and transfer. In our group, detailed electrochemical and PEC characterizations have been performed in the past on SWCNT/TiO2, GO/TiO2 and CD/TiO2 electrodes. However, the physicochemical mechanisms in C/TiO2 hybrids are complex and elusive to a generalized discussion. In this communication, the focus is set on electrode sintering, which is typically performed between 350-550 °C. When electrodes are treated under air atmosphere, carbon nanostructures can be logically altered. Still, certain improvements are found in the photocurrent density of water splitting (Figure 1). Therefore, the role of carbon nanostructures must be understood as a templating or surface conditioner, rather than a direct way for charge mobility.

Financial support from Spanish MICIN/AE/10.13039/501100011033 and "ERDF a way of making Europe" under project grant PID2022-139671OB-I00, as well as by the Gobierno de Aragón (DGA) under project T03_23R (Grupo de Investigación Reconocido) is acknowledged.

1 figure.-- Abstract of the oral communication presented at HeteroNanoCarb 2025, January 13-17, 2025, Benasque (Aragon), Spain.