As a new type of photocatalyst, elemental bismuth has attracted wide attentions for energy conversion and environmental remediation. In this review, the photocatalytic mechanism of elemental Bi including photosensitization, photocatalysis and plasma resonance is discussed. In addition, the main preparation methods such as precipitation, solvothermal and electrochemical methods are described as well. Moreover, the influences of surface active agents, reaction temperature and pH values on the synthesis of bismuth particles are discussed in details. Generally, the optical properties of bismuth are strongly affected by its size and morphology, which is one of the key factors for photocatalytic applications. Besides, bismuth-semiconductor composites including Bi-titanium dioxide, Bi-bismuth oxides, Bi-zinc oxides and Bi-C₃N₄ are also reported as a kind of promising non-noble metal photocatalysts due to their enhanced oxygen vacancy density and increased photo-generated carriers mobility caused by the formation of heterojunction, which could be prepared by one-step hydrothermal process or reduction methods through polybasic alcohol or light irradiation. Furthermore, the narrowed band gap of the compound and the plasma resonance effect of bismuth are also demonstrated to be the reasons for the enhanced photocatalytic activities. Finally, on the basis of the above work, the development of Bi-semiconductor composite photocatalysts is discussed and the opinions on future trend are presented as well.

Contents
1 Introduction
2 Bismuth photocatalyst
2.1 The photocatalytic mechanism of bismuth
2.2 The relationship among the size, morphology, absorption of bismuth
2.3 The preparation methods of bismuth
3 Bismuth composite photocatalysts
3.1 Bi-TiO₂
3.2 Bi-bismuth oxides
3.3 Bi-other semiconductors
4 Conclusion