Photovoltaic electrode material based on onion carbon and preparation method and application thereof

The invention provides a photovoltaic electrode material based on onion carbon and a preparation method and application thereof. The preparation method comprises the following steps: S1, preparing nano-diamond by utilizing a detonation method; s2, acidizing the nano-diamond by adopting a mixed acid solution of H2SO4 and HNO3, and filtering and dispersing after acidizing to obtain a dispersion solution; s3, the dispersion liquid is dried and annealed, and nano onion carbon is prepared; and S4, sequentially manufacturing an electron transport layer, an active layer and a hole transport layer on the surface of the ITO, then coating the hole transport layer with the nano onion carbon, and manufacturing a metal electrode on the nano onion carbon to prepare the photovoltaic electrode material based on the onion carbon. The nano onion carbon is introduced between the hole transport layer and the metal electrode, so that the consumption of the metal electrode is reduced, and the energy conversion efficiency of the so