Effect of Nb/C ratio in the morphological, structural, optical and photocatalytic properties of novel and inexpensive Nb 2 O 5 /carbon xerogel composites - Moraes, Nícolas Perciani de; Bacani, Rebeca; Silva, Maria Lucia Caetano Pinto da; Campos, Tiago Moreira Bastos; Thim, Gilmar Patrocínio; Rodrigues, Liana Alvares (Ceramics International, 2018)