In response to the global energy crisis and environmental challenges，photocatalytic hydrogen （H₂） production has emerged as a sustainable alternative toward clean energy conversion. Among diverse photocatalysts investigated，TiO₂-based nanomaterials have attracted significant attention due to their unique physicochemical properties，such as high chemical stability，strong redox capacity and tunable electronic structures，along with high cost-effectiveness. Extensive research on TiO₂-based photocatalysts proves their enormous potential in the field of H₂ production. This timely and critical review explores the recent advances in TiO₂-based photocatalysts，discussing their distinctive advantages and synthesis methods in photocatalytic H₂ production. Modification strategies，such as elemental doping （e.g.，precious metals，non-precious metals and non-metals），morphology engineering and composite formation，are summarised to improve photocatalytic efficiency. Advanced in/ex situ characterization techniques employed to probe photocatalytic mechanisms are also highlighted. Finally，major challenges，such as limited visible-light activity and charge recombination，are outlined，with perspectives on emerging TiO₂-based nanomaterials and design strategies to overcome current bottlenecks. And the research focus in the future is prospected，such as atomic interface engineering，machine learning auxiliary material design and large-scale preparation technology. This work aims to provide insights into the rational design of TiO₂-based photocatalysts for next-generation H₂ production systems.

Contents

1 Introduction

2 Unique advantages of TiO₂-based photocatalysts

3 Various preparation methods of TiO₂-based photocatalysts

3.1 Top-down synthesis

3.2 Bottom-up synthesis

4 Design strategies of TiO₂-based photocatalysts for H₂ production

4.1 Elemental doping

4.2 Morphology engineering

4.3 Composite

5 Advanced characterization techniques for TiO₂-based photocatalysts

5.1 X-ray diffraction （XRD）

5.2 XPS

5.3 X-ray absorption spectroscopy （XAS）

5.4 TEM and SEM

5.5 Raman and FTIR

6 Conclusions and outlook